3-oxo-2,3-dihydro-1H-isoindole-4-carboxamides as PARP inhibitors

ABSTRACT

There are provided substituted 3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide derivatives (I) which selectively inhibit the activity of poly (ADP-ribose) polymerase PARP-1 with respect to poly (ADP-ribose) polymerase PARP-2. The compounds of this invention are therefore useful in treating diseases such as cancer, cardiovascular diseases, central nervous system injury and different forms of inflammation. The present invention also provides methods for preparing these compounds, pharmaceutical compositions comprising these compounds, and methods of treating, diseases utilizing pharmaceutical compositions comprising these compounds.

The present invention provides substituted 3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide derivatives which selectively inhibit the activity of poly (ADP-ribose) polymerase PARP-1 with respect to poly (ADP-ribose) polymerase PARP-2. The compounds of this invention are therefore useful in treating diseases such as cancer, cardiovascular diseases, central nervous system injury and different forms of inflammation. The present invention also provides methods for preparing these compounds, pharmaceutical compositions comprising these compounds, and methods of treating diseases utilizing pharmaceutical compositions comprising these compounds.

Poly (ADP-ribose) polymerases belong to a family of 18 members that catalyze the addition of ADP-ribose units to DNA or different acceptor proteins, which affect cellular processes as diverse as replication, transcription, differentiation, gene regulation, protein degradation and spindle maintenance. PARP-1 and PARP-2 are the only enzymes among the PARPs that are activated by DNA damage and are involved in DNA repair.

PARP-1 is a nuclear protein consisting of three domains: the N-terminal DNA-binding domain containing two zinc fingers, the auto modification domain, and the C-terminal catalytic domain. PARP-1 binds through the zinc-finger domain to DNA single strand breaks (SSB), cleaves NAD+, and attaches multiple ADP-ribose units to target proteins such as histones and various DNA repair enzymes. This results in a highly negatively charged target, which in turn leads to the unwinding and repair of the damaged DNA through the base excision repair pathway. In knock out mouse models, deletion of PARP-1 impairs DNA repair but it is not embryonic lethal. Double knock out PARP-1 and PARP-2 mice instead die during early embryogenesis, suggesting that the two enzymes display not completely overlapping functions. Enhanced PARP-1 expression and/or activity have been shown in different tumor cell lines, including malignant lymphomas, hepatocellular carcinoma, cervical carcinoma, colorectal carcinoma, leukemia. This may allow tumor cells to withstand genotoxic stress and increase their resistance to DNA-damaging agents. As a consequence, inhibition of PARP-1 through small molecules has been shown to sensitize tumor cells to cytotoxic therapy (e.g. temozolomide, platinums, topoisomerase inhibitors and radiation). A significant window seems to exist between the ability of a PARP inhibitor to potentiate therapeutic benefits and undesirable side effects. Whereas the therapeutic use of PARP inhibitors in combination with DNA damaging agents is not novel, the use of these agents as monotherapy, in particular tumor genetic backgrounds deficient in the homologous recombination DNA repair, represents a new approach. Individuals with heterozygous germ line mutations in either the BRCA-1 or BRCA-2 homologous recombination repair genes exhibit high life time risks of developing breast and other cancers. Tumors arising in mutation carriers have generally lost the wild type allele and do not express functional BRCA-1 and BRCA-2 proteins.

Therefore, loss of these two proteins leads to a tumor-specific dysfunction in the repair of double strand breaks by homologous recombination. It is known that when PARP-1 is inhibited, base excision repair is reduced and single strand breaks that are generated during the normal cell cycle persist. It has also been established that replication forks that encounter an unrepaired break can form double strand breaks which are normally repaired by homologous recombination. Tumor cells that are deficient in homologous recombination repair such as BRCA-1 and BRCA-2 mutants are therefore highly sensitive to PARP inhibition compared with wild-type cells. This is in line with the concept of synthetic lethality, in which the two pathway defects alone are innocuous but combined become lethal: PARP inhibitors may be more effective in patients with tumors with specific DNA repair defects without affecting normal heterozygous tissues. Putative patient population includes, besides BRCA mutants that represent the majority of hereditary breast and ovarian cancer, also a substantial fraction of sporadic cancers with defects in homologous recombination repair, a phenomenon termed “BRCAness”. For example, methylation of the promoters of the BRCA-1 or FANCF genes and amplification of the EMSY gene, which encodes a BRCA-2 interacting protein. By extending the rational of synthetic lethality of PARP and BRCA-1 and BRCA-2, it is likely that deficiencies in any gene that is not redundant in double strand break repair should be sensitive to PARP inhibition. For example, ATM deficiency, found in patients with T-cell prolymhocytic leukemia and B-cell chronic lymphocitic leukemia and breast cancer and CHK2 germ line mutations identified in sarcoma, breast cancer, ovarian cancer and brain tumors, have also been shown to be synthetically lethal in combination with PARP deficiency as well as deficiencies in other known HR pathway proteins (including RAD51, DSS1, RAD54, RPA1, NBS1, ATR, CHK1, CHK2, FANCD2, FANCA, and FANCC).

Mutations in FANCC and FANCG have been shown in pancreatic cancer. Methylation of FANCF promoter has been found in ovarian, breast, cervical, lung carcinomas. The first clinical evidence that BRCA-mutated cancer may be sensitive to PARP inhibitor monotherapy comes from the preliminary data for the phase I trial of the oral, small molecule PARP inhibitor, AZD2281. In an enriched phase I population for BRCA mutation carriers, partial responses were seen in 4 out of 10 ovarian cancer patients with confirmed BRCA-1 mutations. Other PARP inhibitors, such as AG014699, BSI-201, are currently known to be in phase II clinical trials both in combination with DNA damaging agents and as single agent in BRCA deficient tumors. Early indications are that these therapies show low toxicity. Anyway compounds with high selectivity on PARP-1 are expected to show even less toxicity in view of a chronic treatment schedule.

PARP-1 has also been implicated in angiogenesis. In particular, PARP-1 inhibition seems to result in decreased accumulation of the transcription hypoxia-inducible factor 1α, an important regulator of tumor cell adaptation to hypoxia.

Pro-inflammatory stimuli trigger the release of pro-inflammatory mediators that induce the production of peroxynitrate and hydroxyl radicals, which in turn yield to DNA single strand breakage with consequent activation of PARP-1. Over activation of PARP-1 results in depletion of NAD+ and energy stores, culminating in cell dysfunction and necrosis. This cellular suicide mechanism has been implicated in the pathomechanism of stroke, myocardial ischemia, diabetes, diabetes-associated cardiovascular dysfunction, shock, traumatic central nervous system injury, arthritis, colitis, allergic encephalomyelitis and various other forms of inflammation. Of special interest is the enhancement by PARP-1 of nuclear factor kB-mediated transcription, which plays a central role in the expression of inflammatory cytokines, chemokines and inflammatory mediators.

WO2007047646 in the name of Janssen Pharmaceutica describes substituted dihydro isoindolones useful for treating kinase disorders; Wender et al. claim in U.S. Pat. No. 7,232,842 isoindolone analogs as kinase inhibitors. The Patent Application Publication US 2008/0108659 of Gandhi et al. describes 3-oxo-2,3-dihydro-1H-isoindolesas poly (ADP-Ribose) polymerase inhibitors, also reported in: Bioorg. Med. Chem. Lett., 2010, 20, 1023-1026.

The present invention provides novel substituted 3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide derivatives which selectively inhibit the activity of poly (ADP-ribose) polymerase PARP-1 with respect to poly (ADP-ribose) polymerase PARP-2. The compounds herein described are therefore useful in treating proliferative diseases such as cancer and in cardiovascular diseases, nervous system injury and inflammation.

The present invention also provides method for preparing these compounds, pharmaceutical compositions comprising these compounds, and methods of treating diseases utilizing pharmaceutical compositions comprising these compounds.

Accordingly, a first object of the present invention is to provide a compound of the formula (I):

wherein R is:

-   -   either a linear or branched C₁-C₆ alkyl, C₂-C₆ alkenyl or C₂-C₆         alkynyl group, each group substituted with one or more         substituents independently selected from either NR₃R₄, OC₁-C₆         alkyl, CO₂C₁-C₆ alkyl, and CONR_(a)R_(b) group, wherein R_(a)         and R_(b) independently represent a C₂-C₆ alkenyl, C₂-C₆         alkynyl, R₆R₇N—C₂-C₆ alkyl, R₆O—C₂-C₆ alkyl, an optionally         further substituted linear or branched C₁-C₆ alkyl, C₃-C₆         cycloalkyl, heterocyclyl, aryl or heteroaryl, or R_(a) and         R_(b), taken together with the nitrogen atom to which they are         bonded, form an optionally substituted heterocyclyl group; or         from C₃-C₆ cycloalkyl, heterocyclyl, aryl and heteroaryl group,         each of which further substituted with a R₅O—C₁-C₆ alkyl,         R₅O—C₁-C₆ alkyl-NH, R₅O—C₁-C₆ alkyl-O or R₉—C₁-C₆ alkyl group;     -   or a C₃-C₇ cycloalkyl, heterocyclyl, aryl or heteroaryl group,         each of which further substituted with R₅O—C₁-C₆ alkyl, C₃-C₆         cycloalkyl, heterocyclyl, aryl, R₉—C₁-C₆ alkyl or heteroaryl         group, each of which further substituted with one or more         substituents independently selected from halogen atom, cyano,         nitro, NHCOR₂, COR₂, NR₃R₄, NR₃COR₂, oxo (═O), OR₅, SR₅, SOR₉,         SO₂R₉, NHSOR₉, NHSO₂R₉ and an optionally substituted linear or         branched C₁-C₆ alkyl group; when simultaneously present, two         substituents such as NR₃R₄, OR₅, SR₅ may form, taken together,         an optionally substituted heterocyclyl group;         R₁ is hydrogen or halogen atom or cyano, nitro, NHCOR₂, COR₂,         NR₃R₄, NR₃COR₂, OR₅, SR₅, SOR₈, SO₂R₈, NHSOR₈, NHSO₂R₈, an         optionally further substituted linear or branched C₁-C₆ alkyl,         C₂-C₆ alkenyl, C₂-C₆ alkynyl, C₃-C₆ cycloalkyl, heterocyclyl,         aryl or heteroaryl group;         R₂ is hydrogen atom or a C₂-C₆ alkenyl, C₂-C₆ alkynyl, NR₃R₅,         OR₅, SR₅, R₆R₇N—C₁-C₆ alkyl, R₆O—C₁-C₆ alkyl, an optionally         further substituted linear or branched C₁-C₆ alkyl, C₃-C₆         cycloalkyl, heterocyclyl, aryl or heteroaryl group;         R₃ and R₄ are independently hydrogen atom, or a C₂-C₆ alkenyl,         C₂-C₆ alkynyl, R₆R₇N—C₂-C₆ alkyl, R₆O—C₂-C₆ alkyl, an optionally         further substituted linear or branched C₁-C₆ alkyl, C₃-C₆         cycloalkyl, heterocyclyl, aryl or heteroaryl, or         R₃ and R₄, taken together with the nitrogen atom to which they         are bonded, form an optionally substituted heterocyclyl group;         R₅ is hydrogen atom, or a C₂-C₆ alkenyl, C₂-C₆alkynyl, COR₃,         SOR₈, SO₂R₈, R₆R₇N—C₂-C₆ alkyl, R₆O—C₂-C₆ alkyl, an optionally         further substituted linear or branched C₁-C₆ alkyl, C₃-C₆         cycloalkyl, heterocyclyl, aryl or heteroaryl group, wherein R₃         is as defined above;         R₆ and R₇ are independently hydrogen atom, or a C₂-C₆ alkenyl,         C₂-C₆ alkynyl, COR₂, an optionally further substituted linear or         branched C₁-C₆ alkyl, C₃-C₆ cycloalkyl, heterocyclyl, aryl or         heteroaryl group, or R₆ and R₇, taken together with the nitrogen         atom to which they are bonded, form an optionally substituted         heterocyclyl group, wherein R₂ is as defined above;         R₈ is hydrogen atom, or a C₂-C₆ alkenyl, C₂-C₆ alkynyl, NR₃R₄,         OR₅, R₆R₇N—C₁-C₆ alkyl, R₆O—C₁-C₆ alkyl, an optionally further         substituted linear or branched C₁-C₆ alkyl, C₃-C₆ cycloalkyl,         heterocyclyl, aryl or heteroaryl group, wherein R₃, R₄, R₅, R₆         and R₇ are as defined above;         R₉ is either a C₃-C₆ cycloalkyl, heterocyclyl, aryl or         heteroaryl group further substituted with one or more         substituents independently selected from halogen atom, linear or         branched C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, cyano,         nitro, NHCOR₂, COR₂, NR₃R₄, NR₃COR₂, OR₅, SRS, SOR₈, SO₂R₈,         NHSOR₈, NHSO₂R₈, substituted C₁-C₆ alkyl, C₃-C₆ cycloalkyl,         heterocyclyl, aryl and heteroaryl group;         or an optionally substituted C₃-C₆ cycloalkyl, heterocyclyl,         aryl or heteroaryl group fused with a C₃-C₆ cycloalkyl,         heterocyclyl, aryl or heteroaryl group, wherein R₂, R₃, R₄, R₅         and R₈ are as defined above; with the proviso that the compound         1H-isoindole-4-carboxamide,         2,3-dihydro-2-(3-methoxypropyl)-3-oxo is excluded,         or a pharmaceutically acceptable salt thereof.

The compounds of formula (I) as defined above are potent and selective PARP-1 inhibitors with respect to PARP-2 and are thus useful in cancer, cardiovascular diseases, nervous system injury and inflammation therapy.

The present invention also provides methods of synthesizing 3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide derivatives of formula (I) as defined above prepared through a process consisting of standard synthetic transformations.

The present invention also provides methods for treating diseases mediated by the PARP-1 protein.

A preferred method of the present invention is to treat a disease mediated by PARP-1 protein selected from the group consisting of cancer, cardiovascular diseases, nervous system injury and inflammation.

Another preferred method of the present invention is to treat specific types of cancer including but not limited to: carcinoma such as bladder, breast, colon, kidney, liver, lung, including small cell lung cancer, esophagus, gall-bladder, ovary, pancreas, stomach, cervix, thyroid, prostate, and skin, including squamous cell carcinoma; hematopoietic tumors of lymphoid lineage including leukaemia, acute lymphocytic leukaemia, acute lymphoblastic leukaemia, B-cell lymphoma, T-cell-lymphoma, Hodgkin's lymphoma, non-Hodgkin's lymphoma, hairy cell lymphoma and Burkitt's lymphoma; hematopoietic tumors of myeloid lineage, including acute and chronic myelogenous leukemias, myelodysplastic syndrome and promyelocytic leukaemia; tumors of mesenchymal origin, including fibrosarcoma and rhabdomyosarcoma; tumors of the central and peripheral nervous system, including astrocytoma, neuroblastoma, glioma and schwannomas; other tumors, including melanoma, seminoma, teratocarcinoma, osteosarcoma, xeroderma pigmentosum, keratoxanthoma, thyroid follicular cancer and Kaposi's sarcoma.

Another preferred method of the present invention is to treat specific types of cardiovascular diseases including but not limited to: myocardial reperfusion injury, cardiomyopathy, diabetic cardiovascular dysfunction.

Another preferred method of the present invention is to treat specific types of central nervous system injury including but not limited to stroke, brain injury and neurodegenerative disorders.

The present invention further provides a method of treatment comprising a compound of formula (I) as defined above in combination with radiation therapy or chemotherapy regimen for simultaneous, separate or sequential use in anticancer therapy.

Moreover the invention provides a method for selectively inhibiting the PARP-1 protein activity which comprises contacting the said protein with an effective amount of a compound of formula (I) as defined above.

The present invention also provides a pharmaceutical composition comprising one or more compounds of formula (I) as defined above or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable excipient, carrier or diluent.

The present invention also provides a pharmaceutical composition comprising a compound of formula (I) in combination with known cytostatic or cytotoxic agents, antibiotic-type agents, alkylating agents, antimetabolite agents, hormonal agents, immunological agents, interferon-type agents, cyclooxygenase inhibitors (e.g. COX-2 inhibitors), matrix metalloprotease inhibitors, telomerase inhibitors, tyrosine kinase inhibitors, anti-growth factor receptor agents, anti-HER agents, anti-EGFR agents, anti-angiogenesis agents (e.g. angiogenesis inhibitors), farnesyl transferase inhibitors, ras-raf signal transduction pathway inhibitors, cell cycle inhibitors, other cdks inhibitors, tubulin binding agents, topoisomerase I inhibitors, topoisomerase II inhibitors, and the like.

Additionally, the invention provides a product or kit comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof, as defined above, or pharmaceutical compositions thereof and one or more chemotherapeutic agents, as a combined preparation for simultaneous, separate or sequential use in anticancer therapy.

In yet another aspect, the invention provides a compound of formula (I) or a pharmaceutically acceptable salt thereof, as defined above, for use as a medicament.

Moreover the invention provides the use of a compound of formula (I) or a pharmaceutically acceptable salt thereof, as defined above, in the manufacture of a medicament with antitumor activity.

Finally, the invention provides a compound of formula (I) or a pharmaceutically acceptable salt thereof, as defined above, for treating cancer.

The present invention also provides methods of synthesizing the substituted derivatives of formula (I) prepared through a process consisting of standard synthetic transformations.

The compounds of formula (I) may have one or more asymmetric centers, and may therefore exist as individual optical isomers or racemic mixtures or diastereoisomer. Accordingly, all the possible isomers, and their mixtures of the compounds of formula (I) are within the scope of the present invention. As stated above, salts of the compounds of formula (I) are also within the scope of the present invention.

Unless otherwise specified, when referring to the compounds of formula (I) per se as well as to any pharmaceutical composition thereof or to any therapeutic treatment comprising them, the present invention includes all of the isomers, tautomers, hydrates, solvates, N-oxides and pharmaceutically acceptable salts of the compounds of this invention.

If a chiral center or another form of an isomeric center is present in a compound of the present invention, all forms of such isomer or isomers, including enantiomers and diastereomers, are intended to be covered herein. Compounds containing a chiral center may be used as a racemic mixture, an enantiomerically enriched mixture, or the racemic mixture may be separated using well-known techniques and an individual enantiomer may be used alone. In cases in which compounds have unsaturated carbon-carbon double bonds, both the cis (Z) and trans (E) isomers are within the scope of this invention.

In cases wherein compounds may exist in tautomeric forms, such as keto-enol tautomers, each tautomeric form is contemplated as being included within this invention whether existing in equilibrium or predominantly in one form.

With the term halogen atom we intend a fluorine, chlorine, bromine or iodine atom.

With the term cyano we intend a —CN residue.

With the term nitro we intend a —NO₂ group.

With the term “straight or branched C₁-C₆ alkyl”, we intend any of the groups such as, for instance, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, n-hexyl, and the like.

With the term “C₂-C₆ alkenyl” we intend an aliphatic C₂-C₆ hydrocarbon chain containing at least one carbon-carbon double bond and which can be straight or branched. Representative examples include, but are not limited to, ethenyl, 1-propenyl, 2-propenyl, 1- or 2-butenyl, and the like.

With the term “C₂-C₆ alkynyl” we intend an aliphatic C₂-C₆ hydrocarbon chain containing at least one carbon-carbon triple bond and which can be straight or branched. Representative examples include, but are not limited to, ethynyl, 1-propynyl, 2-propynyl, 1- or 2-butynyl, and the like.

With the term “substituted C₁-C₆ alkyl” we intend an aliphatic C₁-C₆ hydrocarbon straight or branched chain containing at least one or more substituents independently selected from halogen, cyano, nitro, NHCOR₂, COR₂, NR₃R₄, NR₃COR₂, OR₅, SR₅, SOR₈, SO₂R₈, NHSOR₈, NHSO₂R₈.

With the term “C₃-C₇ cycloalkyl” we intend, unless otherwise provided, a 3- to 7-membered all-carbon monocyclic ring, which may contain one or more double bonds but does not have a completely conjugated π-electron system. Examples of cycloalkyl groups, without limitation, are cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclohexane, cyclohexene and cyclohexadiene.

With the term “heterocyclyl” we intend a 3- to 8-membered, saturated or partially unsaturated carbocyclic ring where one or more carbon atoms are replaced by heteroatoms such as nitrogen, oxygen and sulfur. Non limiting examples of heterocyclyl groups are, for instance, pyrane, pyrrolidine, pyrroline, imidazoline, imidazolidine, pyrazolidine, pyrazoline, thiazoline, thiazolidine, dihydrofuran, tetrahydrofuran, 1,3-dioxolane, piperidine, piperazine, morpholine and the like.

The term “aryl” refers to a mono-, bi- or poly-carbocyclic hydrocarbon with from 1 to 4 ring systems, optionally further fused or linked to each other by single bonds, wherein at least one of the carbocyclic rings is “aromatic”, wherein the term “aromatic” refers to completely conjugated π-electron bond system. Non limiting examples of such aryl groups are phenyl, α- or β-naphthyl or biphenyl groups.

The term “heteroaryl” refers to aromatic heterocyclic rings, typically 5- to 8-membered heterocycles with from 1 to 3 heteroatoms selected among N, O or S; the heteroaryl ring can be optionally further fused or linked to aromatic and non-aromatic carbocyclic and heterocyclic rings. Not limiting examples of such heteroaryl groups are, for instance, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, imidazolyl, thiazolyl, isothiazolyl, pyrrolyl, phenyl-pyrrolyl, furyl, phenyl-furyl, oxazolyl, isoxazolyl, pyrazolyl, thienyl, benzothienyl, isoindolinyl, benzoimidazolyl, indazolyl, quinolinyl, isoquinolinyl, 1,2,3-triazolyl, 1-phenyl-1,2,3-triazolyl, 2,3-dihydroindolyl, 2,3-dihydrobenzofuranyl, 2,3-dihydrobenzothiophenyl; benzopyranyl, 2,3-dihydrobenzoxazinyl, 2,3-dihydroquinoxalinyl and the like.

According to the present invention and unless otherwise provided, when any of the above groups is optionally substituted, it may be substituted in any of its free positions, by one or more groups, for instance 1 to 6 groups, independently selected from: halogen, nitro, oxo groups (═O), cyano, C₁-C₆ alkyl, polyfluorinated alkyl, polyfluorinated alkoxy, C₂-C₆ alkenyl, C₂-C₆ alkynyl, hydroxyalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, heterocyclyl, heterocyclylalkyl, C₃-C₇ cycloalkyl, hydroxy, alkoxy, aryloxy, heterocyclyloxy, methylenedioxy, alkylcarbonyloxy, arylcarbonyloxy, cycloalkenyloxy, heterocyclylcarbonyloxy, alkylideneaminooxy, carboxy, alkoxycarbonyl, aryloxycarbonyl, cycloalkyloxycarbonyl, heterocyclylalkyloxycarbonyl-amino, ureido, alkylamino, dialkylamino, arylamino, diarylamino, heterocyclylamino, formylamino, alkylcarbonylamino, arylcarbonylamino, heterocyclylcarbonylamino, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, arylaminocarbonyl, heterocyclylaminocarbonyl, alkoxycarbonylamino, hydroxyaminocarbonyl alkoxyimino, alkylsulfonylamino, arylsulfonylamino, heterocyclylsulfonylamino, formyl, alkylcarbonyl, arylcarbonyl, cycloalkylcarbonyl, heterocyclylcarbonyl, alkylsulfonyl, arylsulfonyl, aminosulfonyl, alkylaminosulfonyl, dialkylaminosulfonyl, arylaminosulfonyl, heterocyclylaminosulfonyl, arylthio, alkylthio, phosphonate and alkylphosphonate. In their turn, whenever appropriate, each of the above substituent may be further substituted by one or more of the aforementioned groups.

With the term polyfluorinated alkyl or polyfluorinated alkoxy we intend any of the above straight or branched C₁-C₆ alkyl or alkoxy groups which are substituted by more than one fluorine atom such as, for instance, trifluoromethyl, trifluoroethyl, 1,1,1,3,3,3-hexafluoropropyl, trifluoromethoxy and the like.

With the term hydroxyalkyl we intend any of the above C₁-C₆ alkyl, bearing an hydroxyl group such as, for instance, hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl and the like.

From all of the above, it is clear to the skilled person that any group which name is a composite name such as, for instance, arylamino has to be intended as conventionally construed by the parts from which it derives, e.g. by an amino group which is further substituted by aryl, wherein aryl is as above defined.

Likewise, any of the terms such as, for instance, alkylthio, alkylamino, dialkylamino, alkoxycarbonyl, alkoxycarbonylamino, heterocyclylcarbonyl, heterocyclylcarbonylamino, cycloalkyloxycarbonyl and the like, include groups wherein the alkyl, alkoxy, aryl, C₃-C₇ cycloalkyl and heterocyclyl moieties are as above defined.

The term “pharmaceutically acceptable salt” of compounds of formula (I) refers to those salts that retain the biological effectiveness and properties of the parent compound, therefore pharmaceutically acceptable salts of the compounds of formula (I) include the acid addition salts with inorganic or organic acids, e.g., nitric, hydrochloric, hydrobromic, sulfuric, perchloric, phosphoric, acetic, trifluoroacetic, propionic, glycolic, (D) or (L) lactic, oxalic, ascorbic, fumaric, malonic, malic, maleic, tartaric, citric, benzoic, cinnamic, mandelic, methanesulphonic, ethanesulfonic, p-toluenesulfonic, isethionic, succinic and salicylic acid.

Pharmaceutically acceptable salts of the compounds of formula (I) also include the salts with inorganic or organic bases, e.g., alkali or alkaline-earth metals, especially sodium, potassium, calcium, ammonium or magnesium hydroxides, carbonates or bicarbonates, acyclic or cyclic amines, preferably methylamine, ethylamine, diethylamine, triethylamine, piperidine and the like.

In a first preferred embodiment, the present invention provides compounds of formula (I) characterized in that R is a linear or branched C₁-C₆ alkyl substituted with one or more substituents independently selected from either NR₃R₄ or C₃-C₆ cycloalkyl, heterocyclyl, aryl and heteroaryl group, further substituted with R₅O—C₁-C₆ alkyl, R₅O—C₁-C₆ alkyl-NH, R₅O—C₁-C₆ alkyl-0 or R₅—C₁-C₆ alkyl group, and R₁ is hydrogen or halogen atom or cyano, nitro, NHCOR₂, NR₃R₄, NR₃COR₂, OR₅, an optionally further substituted linear or branched C₁-C₆ alkyl, C₂-C₆ alkenyl or C₂-C₆ alkynyl group, wherein R₂, R₃, R₄, R₅, and R₉ are as defined above, or a pharmaceutically acceptable salt thereof.

In a more preferred embodiment, the present invention provides compounds of general formula (I) characterized in that R is a C₃-C₇ cycloalkyl, heterocyclyl, aryl or heteroaryl group, each of which further substituted with R₅O—C₁-C₆ alkyl, C₃-C₆ cycloalkyl, R₅—C₁-C₆ alkyl, heterocyclyl, aryl or heteroaryl group, each of which further substituted with one or more substituents independently selected from halogen atom, cyano, nitro, NHCOR₂, NR₃R₄, NR₃COR₂, oxo (═O), OR₅ and a substituted C₁-C₆ alkyl group; when simultaneously present, two substituents such as NR₃R₄, OR₅, may form, taken together, an optionally substituted heterocyclyl group, and R₁ is hydrogen or halogen atom or OR₅, optionally further substituted linear or branched C₁-C₆ alkyl; wherein R₂, R₃, R₄, R₅ and R₉ are as defined above, or a pharmaceutically acceptable salt thereof.

Even more preferably, the present invention provides compounds of the formula (I) as defined above characterized in that: R is

-   -   either a linear or branched C₁-C₆ alkyl group substituted with         one or more substituents independently selected from a NR₃R₄,         OC₁-C₆ alkyl, CO₂C₁-C₆ alkyl, CONR_(a)R_(b) group, wherein R_(a)         and R_(b) independently represent a linear or branched C₁-C₆         alkyl or a R₆R₇N—C₂-C₆ alkyl group, or R_(a) and R_(b), taken         together with the nitrogen atom to which they are bonded, form         an optionally substituted heterocyclyl group, wherein the         substituent is a C₁-C₆ alkyl or aryl group; and a heterocycly         group further substituted with a substituted aryl or an         optionally substituted aryl-C₁-C₆ alkyl group, wherein the         substituent is one or more independently selected from halogen         atom and C₁-C₆ alkyl group;     -   or a heterocyclyl group further substituted with R₅O—C₁-C₆         alkyl, C₃-C₆ cycloalkyl or R₅—C₁-C₆ alkyl group, each of which         further substituted with one or more substituents independently         selected from halogen atom, oxo (═O), OR₅, when simultaneously         present, two substituents such as OR₅ may form, taken together,         an optionally substituted heterocyclyl group, and an optionally         substituted linear or branched C₁-C₆ alkyl group, wherein the         substituent if present, is hydroxy or O—C₁-C₆ alkyl group;         R₁ is hydrogen or halogen atom;         R₃ and R₄ are independently an optionally further substituted         linear or branched C₁-C₆ alkyl, C₃-C₆ cycloalkyl, or         heteroaryl-C₁-C₆ alkyl group or R₃ and R₄, taken together with         the nitrogen atom to which they are bonded, form an optionally         substituted heterocyclyl group, such substituent being a halogen         atom;         R₅ is an optionally further substituted linear or branched C₁-C₆         alkyl group;         R₆ and R₇ are independently an optionally further substituted         linear or branched C₁-C₆ alkyl group;         R₉ is or a heterocyclyl, aryl or heteroaryl group, each of which         further substituted with one or more substituents independently         selected from halogen atom, linear or branched C₁-C₆ alkyl, or         substituted C₁-C₆ alkyl, wherein the substituent is one or more         selected from halogen atom and aryl group;         or an optionally substituted aryl or heteroaryl group fused with         an aryl group or a heteroaryl group, wherein the substituent is         one or more selected from linear or branched C₁-C₆ alkyl group;         or a pharmaceutically acceptable salt thereof.

Most preferably, the present invention provides compounds of the formula (I) as defined above characterized in that: R is

-   -   either a methyl, ethyl or propyl group substituted with one or         more substituents independently selected from a NR₃R₄, OCH₃,         CO₂CH₃, CONR_(a)R_(b) group, wherein R_(a) and R_(b)         independently represent a methyl or a dimethylaminoethyl group,         or R_(a) and R_(b), taken together with the nitrogen atom to         which they are bonded, form an optionally substituted         piperazinyl or tetrahydropyridyl group, wherein the substituent         is a methyl or phenyl group; and a piperidinyl group further         substituted with a substituted phenyl or an optionally         substituted benzyl group, wherein the substituent is one or more         independently selected from chlorine, fluorine atom and methyl         group;     -   or a piperidinyl group further substituted with methoxyethyl,         cyclohexyl or R₉-methyl group, each of which further substituted         with one or two substituents independently selected from         fluorine atom, oxo (═O), methoxy or, when simultaneously         present, two substituents form, taken together, a dioxolane         ring, and an optionally substituted methyl group, wherein the         substituent if present is hydroxyl or methoxy group;         R₁ is hydrogen or fluorine atom;         R₃ and R₄ are independently an optionally further substituted         i-butyl or methyl, cyclopentyl, or furylmethyl group, or         R₃ and R₄, taken together with the nitrogen atom to which they         are bonded, form an optionally substituted piperidinyl group,         such substituent being a chlorine atom;         R₉ is a piperidinyl, phenyl, thiazolyl, pyrazolyl or pyrrolyl         group, each of which further substituted with one or more         substituents independently selected from chlorine, fluorine or         bromine atom, methyl, ethyl, isopropyl, methoxy, ethoxy,         propyloxy, isopropyloxy, dimethylamino group or substituted         methyl, wherein the substituent is one or more selected from         fluorine atom and phenyl group;         or an optionally substituted phenyl, pyrrolyl or pyridyl group         fused with a phenyl or a pyrrole ring, wherein the substituent         is one or more selected from isopropyl group;         or a pharmaceutically acceptable salt thereof.

Specific compounds of the present invention are listed below:

-   1.     2-[1-(cis-4-methoxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   2.     2-[1-(trans-4-methoxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   3.     2-{1-[cis-4-(hydroxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   4.     2-{1-[trans-4-(hydroxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   5.     2-{1-[cis-4-(methoxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   6.     2-{1-[trans-4-(methoxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   7.     2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   8.     2-[1-(1,4-dioxaspiro[4.5]dec-8-yl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   9. 2-(2-methoxyethyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   10.     2-{1-[4-(dimethylamino)benzyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   11.     2-[1-(4-fluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   12.     2-[1-(2-fluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   13.     2-[1-(3-fluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   14.     2-{1-[(1-methyl-1H-pyrrol-2-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   15.     3-oxo-2-{1-[4-(trifluoromethyl)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; -   16.     3-oxo-2-[1-(quinolin-2-ylmethyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide; -   17.     2-[1-(2,4-difluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   18.     2-[1-(3,4-dimethylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   19.     2-[1-(2-methylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   20.     2-[1-(2-bromobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   21.     2-[1-(3-bromobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   22.     2-[1-(4-bromobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   23.     3-oxo-2-{1-[3-(trifluoromethyl)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; -   24.     3-oxo-2-{1-[2-(trifluoromethyl)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; -   25.     2-[1-(3-methylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   26.     2-{1-[(4-methyl-1,3-thiazol-5-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   27.     2-{1-[(1-benzylpiperidin-4-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   28.     2-[1-(1H-indol-4-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   29.     2-[1-(1H-indol-5-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   30.     2-[1-(1H-indol-6-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   31.     2-[1-(4-methylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   32.     3-oxo-2-(1-{[1-(propan-2-yl)-1H-indol-3-yl]methyl}piperidin-4-yl)-2,3-dihydro-1H-isoindole-4-carboxamide; -   33.     2-{1-[(1-methyl-1H-pyrazol-4-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   34.     2-{1-[(1,5-dimethyl-1H-pyrazol-4-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   35.     2-[1-(3-methoxybenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   36.     2-{1-[(3-methylthiophen-2-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   37.     3-oxo-2-[1-(4-propoxybenzyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide; -   38.     3-oxo-2-{1-[4-(propan-2-yl)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; -   39.     2-[1-(4-methoxybenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   40.     2-[1-(3-ethoxybenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   41.     3-oxo-2-{1-[2-(propan-2-yloxy)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; -   42.     2-[1-(3-chlorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   43.     2-[1-(4-ethylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   44.     3-oxo-2-{1-[4-(propan-2-yloxy)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; -   45.     2-{1-[(5-methylthiophen-2-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   46.     2-{3-[4-(3-chlorophenyl)piperazin-1-yl]propyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   47.     2-{[1-(4-methylbenzyl)piperidin-4-yl]methyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   48.     2-{3-[bis(2-methylpropyl)amino]propyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   49.     2-{[1-(3-methylbenzyl)piperidin-4-yl]methyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   50.     2-{3-[cyclopentyl(furan-2-ylmethyl)amino]propyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   51.     2-{[1-(4-fluorobenzyl)piperidin-4-yl]methyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   52.     2-[1-(cis-4-hydroxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   53.     2-[1-(trans-4-hydroxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   54.     2-{1-[cis-4-(acetylamino)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   55.     2-{1-[trans-4-(acetylamino)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   56.     3-oxo-2-{1-[cis-4-(trifluoromethyl)cyclohexyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; -   57.     3-oxo-2-{1-[trans-4-(trifluoromethyl)cyclohexyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; -   58.     2-{1-[cis-4-(dimethylamino)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   59.     2-{1-[trans-4-(dimethylamino)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   60.     2-[1-(cis-4-carbamoylcyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   61.     2-[1-(trans-4-carbamoylcyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   62.     2-{1-[cis-4-(3-chlorophenyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   63.     2-{1-[trans-4-(3-chlorophenyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   64.     2-[1-(cis-4-cyanocyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   65.     2-[1-(trans-4-cyanocyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   66.     2-{4-[(4,4-difluoropiperidin-1-yl)methyl]phenyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   67.     2-{4-[(4-methoxypiperidin-1-yl)methyl]phenyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   68.     2-{4-[(4-hydroxypiperidin-1-yl)methyl]phenyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   69.     2-(4-{[4-(methoxymethyl)piperidin-1-yl]methyl}phenyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   70.     2-(4-{[4-(hydroxymethyl)piperidin-1-yl]methyl}phenyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   71.     2-[1-(4,4-difluorocyclohexyl)azetidin-3-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   72.     2-[1-(cis-4-methoxycyclohexyl)azetidin-3-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   73.     2-[1-(trans-4-methoxycyclohexyl)azetidin-3-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   74.     2-[1-(cis-4-hydroxycyclohexyl)azetidin-3-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   75.     2-[1-(trans-4-hydroxycyclohexyl)azetidin-3-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   76.     2-{1-[cis-4-(methoxymethyl)cyclohexyl]azetidin-3-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   77.     2-{1-[trans-4-(methoxymethyl)cyclohexyl]azetidin-3-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   78.     2-{1-[cis-4-(hydroxymethyl)cyclohexyl]azetidin-3-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   79.     2-{1-[trans-4-(hydroxymethyl)cyclohexyl]azetidin-3-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   80.     6-fluoro-2-[1-(cis-4-methoxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   81.     6-fluoro-2-[1-(trans-4-methoxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   82.     6-fluoro-2-[1-(cis-4-hydroxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   83.     6-fluoro-2-[1-(trans-4-hydroxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   84.     6-fluoro-2-{1-[cis-4-(methoxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   85.     6-fluoro-2-{1-[trans-4-(methoxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   86.     6-fluoro-2-{1-[cis-4-(hydroxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   87.     6-fluoro-2-{1-[trans-4-(hydroxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   88.     2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   89.     2-[1-(1,4-dioxaspiro[4.5]dec-8-yl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   90.     6-fluoro-2-[1-(4-fluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   91.     6-fluoro-3-oxo-2-[1-(quinolin-2-ylmethyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide; -   92.     6-fluoro-2-{1-[(3-methylthiophen-2-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   93.     6-fluoro-2-[1-(1H-indol-6-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   94.     6-fluoro-2-[1-(1H-indol-5-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   95.     6-fluoro-2-[1-(1H-indol-4-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   96.     6-fluoro-3-oxo-2-(1-{[1-(propan-2-yl)-1H-indol-3-yl]methyl}piperidin-4-yl)-2,3-dihydro-1H-isoindole-4-carboxamide; -   97.     6-fluoro-2-{[1-(4-fluorobenzyl)piperidin-4-yl]methyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   98.     2-({1-[(4,4-difluorocyclohexyl)methyl]piperidin-4-yl}methyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   99.     2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   100.     2-[1-(4,4-difluorocyclohexyl)-piperidin-4-yl]-6-chloro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   101.     2-[1-(4,4-difluorocyclohexyl)-piperidin-4-yl]-7-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   102.     2-[1-(4,4-difluorocyclohexyl)-piperidin-4-yl]-5-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; -   103.     6-fluoro-3-oxo-2-[1-(4-oxocyclohexyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide; -   104.     5-fluoro-3-oxo-2-[1-(4-oxocyclohexyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide; -   105.     2-[1-(4,4-dichlorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide     and -   106.2-[1-(2-methoxyethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide     or a pharmaceutically acceptable salt thereof.

The present invention also provides processes for the preparation of compounds of the formula (I) as defined above.

Accordingly, a process of the present invention comprises one of the following sequence of steps:

Sequence A)

either

Step a) halogenating a compound of formula (IX):

wherein R₁ is as defined above; Step b) cyano-de-aminating the resultant compound of formula (VIII):

wherein Hal is halogen such as Cl, Br, I and R₁ is as defined above; Step c) hydrolyzing the resultant compound of formula (VII):

wherein Hal and R₁ are as defined above and Step d) hydrolyzing the resultant compound of formula (VI):

wherein Hal and R₁ are as defined above, to give a compound of the formula (V):

wherein Hal and R₁ are as defined above; or Step i) halogenating a compound of formula (X):

wherein R₁ is as defined above; Step e) esterifying the resultant compound of formula (V) as defined above and either Step f) cyclizing the resultant compound of formula (IV):

wherein T is a C₁-C₆ alkyl or aryl C₁-C₆ alkyl group; Hal and R₁ are as defined above, by reaction with a suitable amine R—NH₂ of formula (XII), wherein R is as defined above and Step g) cyano-de-halogenating the resultant compound of formula (III):

wherein Hal, R and R₁ are as defined above, to give a compound of formula (II):

wherein R and R₁ are as defined above, or Step g′) cyano-de-halogenating a compound of formula (IV) as defined above, and Step f′) cyclizing the resultant compound of formula (XI):

wherein T and R₁ are as defined above by reacting with a suitable amine of formula (XII) as defined above and Step h) hydrolyzing the resultant compound of formula (II) as defined above to give a compound of formula (I) as defined above; or Sequence B): Step l) a reductive amination step performed on a compound of formula (XIII):

wherein R₁ is as defined above; Step m) a Diels-Alder reaction step performed on the resultant compound of formula (XIV):

wherein R and R₁ are as defined above; Step n) aromatizing the resultant compound of formula (XV):

wherein R and R₁ are as defined above; Step o) amidating the resultant compound of formula (XVI):

wherein R and R₁ are as defined above so as to obtain a compound of formula (I) as defined above, or, alternatively Step p) performing a reductive amination step on a compound of formula (XVII):

wherein R₁ is as defined above, so as to obtain a compound of the formula (XIV) as defined above, which is then subjected to the sequence of reactions m), n) and o) above described so as to obtain a compound of formula (I) as above defined.

If necessary or wanted, the processes above described comprises converting a compound of formula (I) into a different compound of formula (I) by known chemical reactions; and/or, if desired, converting a compound of formula (I) into a pharmaceutically acceptable salt thereof or converting a salt into a free compound of formula (I). Any of the above intermediates or close precursors of a desired compound of (I) may be converted into a different intermediate or close precursor of a compound of formula (I), as for example an intermediate of formula (XVI) as herein defined may be converted into a different compound of formula (XVI), by known chemical reactions.

Such known chemical reactions for possible conversions of compounds into different compounds are for example:

1Cv) a protection of a compound;

2Cv) a deprotection of a compound;

3Cv) a reductive amination.

All the above processes are analogy processes which can be carried out according to well known methods and under suitable conditions known in the art.

The synthesis of a compound of formula (I), according to the synthetic process described above, can be carried out in a stepwise manner, whereby each intermediate is isolated and purified by standard purification techniques, like, for example, column chromatography, before carrying out the subsequent reaction. Alternatively, two or more steps of the synthetic sequence can be carried out in a so-called “one-pot” procedure, as known in the art, whereby only the compound resulting from the two or more steps is isolated and purified.

Schemes 1-2 below show the preparation of a compound of formula (I) as defined above.

According to step a), a compound of formula (VIII) can be obtained by halogenating a compound of formula (IX) in a variety of ways and experimental conditions known in the art. Preferably this reaction is conducted in the presence of N-bromosuccinimide, N-iodosuccinimmide, N-chlorosuccinimide, bromine, iodine, hydrobromic acid/hydrogen peroxide, in a suitable solvent, such as acetonitrile, N,N-dimethylformamide, dioxane, dimethylsulfoxide, acetic acid, water at a temperature ranging from about room temperature to reflux and for a period of time varying from about 1 hour to about 96 hours.

According to step b), a compound of formula (VII) can be obtained by a two-steps reaction sequence from a compound of formula (VIII) in a variety of ways and experimental conditions known in the art. First step is preferably conducted in the presence of sodium nitrite/hydrochloric acid or tert-butylnitrite in a suitable solvent, such as tetrahydrofuran, dimethoxyethane, dimethylsulfoxide, acetic acid, water at a temperature ranging from about −20° C. to room temperature and for a period of time varying from 10 minutes to about 24 hours. Second step is preferably carried out in the presence of sodium, copper or potassium cyanide, often in the presence of an additive such as copper or potassium chloride, in a suitable solvent such as tetrahydrofuran, dimethoxyethane, dimethylsulfoxide, acetic acid, toluene, water at a temperature ranging from about −20° C. to reflux and for a period of time ranging from about 10 minutes to about 96 hours. According to step c), the hydrolysis of a compound of formula (VII) to a compound of formula (VI) can be carried out in a variety of ways, according to conventional methods for transforming a cyano group to amide. Preferably this reaction is carried out in a suitable solvent such as, for instance, methanol, ethanol, butanol, 1,4-dioxane, water, or a mixture thereof, in the presence of a suitable acid or base, such as, for instance, sulfuric acid, hydrochloric acid, sodium hydroxide, sodium carbonate, or a suitable reagent such as hydrogen peroxide or sodium perborate. Typically, the reaction is carried out at a temperature ranging from room temperature to reflux and for a time varying from about 1 hour to about 96 hours.

According to step d), a compound of formula (VI) can be transformed into a compound of formula (V) according to conventional methods. Preferably the reaction is carried out in the presence of water by treatment with a base such as potassium or sodium carbonate, potassium or sodium hydroxide, in a suitable solvent such as, for instance, methanol, ethanol, at a temperature ranging from room temperature to reflux, for a time ranging from about 30 min. to about 96 hours. Alternatively this reaction can be conducted in the persence of sodium nitrite/acetic acid, sulfuric acid, fosforic acid at a temperature ranging from room temperature to reflux and for a time varying from about 1 hour to about 96 hours.

According to step e), a compound of formula (V) can be transformed into a compound of formula (IV) according to conventional methods. Preferably the reaction is carried out in the presence of hydrochloric acid, sulfuric acid, acetic acid by using as a solvent methanol, ethanol, water, or a mixture thereof, at a temperature ranging from room temperature to reflux and for a time varying from about 1 hour to about 96 hours. Alternatively, this reaction can be conducted with alkyl iodide or bromide in the presence of a suitable base such as sodium or potassium carbonate, sodium, lithium or potassium hydroxide at a temperature ranging from room temperature to reflux and for a time varying from about 1 hour to about 96 hours.

According to step f), a compound of formula (III) can be obtained by a two-steps reaction sequence from a compound of formula (IV) in the presence of a compound of formula (XII) in a variety of ways and experimental conditions known in the art. First step is preferably conducted in the presence of N-bromosuccinimide with a radical initiator such as benzoyl peroxide or azobisisobutyronitrile in a suitable solvent, such as carbon tetrachloride, chloroform, dichloromethane or methyl pivalate at a temperature ranging from about room temperature to reflux and for a period of time varying from 10 minutes to about 24 hours. Second step can be conducted both under basic or acidic conditions such as in the presence of sodium or potassium carbonate, 1,8-diazabicyclo[5.4.0]undec-7-ene, triethylamine, N,N-diisopropylethylamine, pyridine or acetic acid, hydrochloric acid in a suitable solvent, such as tetrahydrofuran, dimethoxyethane, 1,4-dioxane, toluene at a temperature ranging from room temperature to reflux and for a period of time varying from 1 hour to about 96 hours.

According to step g), the transformation of a compound of formula (III) into a compound of formula (II) can be carried out in a variety of ways, according to conventional methods for cyanation reactions. Preferably, this reaction is carried out in the presence of copper(I) cyanide or potassium hexacyanoferrate (II) as cyano source in a suitable solvent such as, for instance, methanol, ethanol, tetrahydrofuran, 1,4-dioxane, toluene, xylene, N-methyl-2-pyrrolidone, or a mixture thereof, at a temperature ranging from room temperature to reflux and for a time varying from about 1 hour to about 96 hours. If a catalyst is required, it is usually a metal, most often a palladium derivative such as, for instance, palladium(II) chloride or palladium(II) acetate in the presence of a suitable base such as, for instance, sodium, potassium or cesium carbonate, cesium fluoride.

According to step h), the transformation of a compound of formula (II) into a compound of formula (I) can be carried out in a variety of ways and experimental conditions. Preferably it is carried out in a way analogous to that reported for step c).

According to step i), the halogenation of a compound of formula (X) into a compound of formula (V) can be carried out in a variety of ways, according to conventional methods for halogenation reactions. Preferably, this reaction is carried out with tetrabutylammonium bromide and/or iodine in the presence of phenyliodine(III) bis(trifluoracetate) or phenyliodo(III) diacetate as halogen source in a suitable solvent such as, for instance, N,N-dimethylformamide or dichloroethane, at a temperature ranging from room temperature to reflux and for a time varying from about 1 hour to about 48 hours. The catalyst is usually a metal, most often a palladium derivative such as, for instance, palladium(II) chloride or palladium(II) acetate.

According to step g′) the cyanation of a compound of formula (IV) to give a compound of formula (XI) can be carried out in a variety of ways and experimental conditions. Preferably it is carried out in a way analogous to that reported for step g).

According to step f′) the transformation of a compound of formula (IX) into a compound of formula (II) in the presence of a compound of formula (XII) can be carried out in a variety of ways and experimental conditions. Preferably it is carried out in a way analogous to that reported for step f).

According to step l) the reductive amination of a compound of formula (XIII) to give a compound of formula (XIV), by reaction with a suitable amine of formula (XII), can be conducted in a variety of ways, according to conventional methods for carrying out reductive amination. Preferably, this reaction is carried out in a suitable solvent such as, for instance, methanol, N,N-dimethylformamide, dichloromethane, tetrahydrofuran, benzene, toluene, or a mixture thereof, in the presence of a suitable reducing agent such as, for instance, sodium borohydride, tetraalkylammonium borohydride, sodium cyano borohydride, sodium triacetoxyborohydride, tetramethylammonium triacetoxy borohydride and in the presence of an acid or basic catalyst, such as, for instance, acetic acid, trifluoroacetic acid, zinc chloride, zinc bromide, tin(IV) chloride, titanium(IV) chloride, boron trifluoride or triethylamine, N,N-diisopropylethylamine, pyridine at a temperature ranging from about 0° C. to reflux and for a time varying from about 1 hour to about 96 hours.

According to step m) the Diels-Alder reaction of a compound of formula (XIV) to give a compound of formula (XV) can be conducted in a variety of ways, according to conventional methods for carrying out these reactions. Preferably, this reaction is carried out in a suitable solvent such as, for instance, tetrahydrofuran, benzene, toluene, o-xilene in the presence of maleic anhydride at a temperature ranging from about room temperature to reflux and for a time varying from about 1 hour to about 96 hours.

According to step n) the conversion of a compound of formula (XV) into a compound of formula (XVI) can be carried out in a variety of ways, according to conventional methods. Preferably, this reaction is carried out in a suitable solvent such as, for instance, tetrahydrofuran, toluene, water, in the presence of hydrochloric acid, p-tolensulfonic acid, phosphoric acid, at a temperature ranging from about room temperature to reflux and for a time varying from about 1 hour to about 24 hours.

According to step o) a compound of formula (I) can be obtained by reacting a compound of formula (XVI) in a variety of ways and experimental conditions, which are widely known in the art of condensation reactions. Preferably a compound of formula (XVI) is reacted with ammonia or ammonia source such as ammonium salts, in the presence of an activating agent such as carbonyldiimidazole, benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate, 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate), (O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate, dicyclohexyl carbodiimide, diisopropyl carbodiimide, 1-ethyl-3-(3′-dimethylamino) carbodiimide hydrochloric acid salt, optionally in the presence of hydroxybenzotriazole. Preferably, this reaction is carried out in a suitable solvent such as, for instance, N,N-dimethylformamide, N,M-dimethylacetamide, tetrahydrofuran, dichloromethane, 1,4-dioxane, and in the presence of a proton scavenger such as, for example, pyridine, triethylamine, N,N-diisopropylethylamine, at a temperature ranging from room temperature to reflux, for a time ranging from about 30 minutes to about 96 hours. According to step p) the transformation of a compound of formula (XVII) into a compound of formula (XIV) can be carried out in a variety of ways and experimental conditions. Preferably it is carried out in a way analogous to that reported for step l).

According to the conversion 1 (1Cv) the protection of compound of formula (XVI) to give a compound of formula (XVI) may be carried out in a variety of ways and experimental conditions. Preferably when the protective group is tert-butoxycarbonyl, the reaction may be carried out in the presence of di-tert-butyl dicarbonatein a variety of solvents such as methanol, ethanol, acetonitrile, tetrahydrofuran, dichloromethane in the presence of a base such as pyridine, N,N-dimethylaminopyridine, triethylamine, sodium or potassium carbonate at a temperature ranging from room temperature to reflux and for a time varying from about 1 hour to about 96 hours.

According to the conversion 2 (2Cv) the deprotection of a compound of formula (I) or an intermediate or precursor may be carried out in a variety of ways and experimental conditions. Preferably when the protective group is tert-butoxycarbonyl, the reaction may be carried out in the presence of hydrochloric acid, trifluoroacetic acid in a suitable solvent such as dioxane, dichloromethane, tetrahydrofuran at a temperature ranging from room temperature to reflux and for a time varying from about 1 hour to about 24 hours.

Even more preferably, when the protective group is benzyl, the reaction may be carried out by reacting the starting material, in the presence of a hydrogenation catalyst such as, for instance, palladium on carbon, palladium hydroxide, palladium black, Ni Raney and the like with a suitable reducing agent such as molecular hydrogen, cyclohexene, cyclohexadiene, formic acid, ammonium formate and the like in a suitable solvent such as methanol, ethanol, dioxane and the like at a temperature ranging from room temperature to reflux. Alternatively, this conversion could be accomplished with metals such as tin, iron, zinc and the like in the presence of protic acid such as hydrochloric acid, acetic acid and the like optionally in a suitable solvent such as methanol, ethanol at a temperature ranging from room temperature to reflux for a time varying from about 1 hour to about 24 hours.

According to the conversion 3 (Cv3) the reductive amination of a compound of formula (I) may be carried out in a variety of ways and experimental conditions. Preferably it is carried out in a way analogous to that reported for step l).

Substituted isoindolinone derivatives can be prepared using standard procedures in organic synthesis as reported, for instance, in Smith, Michael—March's Advanced Organic Chemistry: reactions mechanisms and structure—6th Edition, Michael B. Smith and Jerry March, John Wiley & Sons Inc., New York (NY), 2007. It is known to the skilled person that transformation of a chemical function into another may require that one or more reactive centers in the compound containing this function be protected in order to avoid undesired side reactions. Protection of such reactive centers, and subsequent deprotection at the end of the synthetic transformations, can be accomplished following standard procedures described, for instance, in: Green, Theodora W. and Wuts, Peter G. M.—Protective Groups in Organic Synthesis, Third Edition, John Wiley & Sons Inc., New York (NY), 1999.

In cases where a compound of formula (I) contains one or more asymmetric centers, said compound can be separated into the single isomers by procedures known to those skilled in the art. Such procedures comprise standard chromatographic techniques, including chromatography using a chiral stationary phase, or crystallization. General methods for separation of compounds containing one or more asymmetric centers are reported, for instance, in Jacques, Jean; Collet, André; Wilen, Samuel H.,—Enantiomers, Racemates, and Resolutions, John Wiley & Sons Inc., New York (NY), 1981.

A compound of formula (I) can also be transformed into a pharmaceutically acceptable salt according to standard procedures that are known to those skilled in the art. Alternatively, a compound of formula (I) that is obtained as a salt can be transformed into the free base or the free acid according to standard procedures that are known to the skilled person.

The starting materials of the process of the present invention, i.e. compounds of formula (IX), (X), (XII), (XIII) and (XVII) are either commercially available or can be prepared by using well-known methods.

For example, the compound of formula (XVII) can be easily obtained according to conventional procedures, which are widely known in the art for reductive amination reactions (see for example Lehmann, F.; Scobie, M. Synthesis, 2008, 1679-1681.

Biochemical Assay

Affinity evaluation of the tested compounds and their selectivity with respect to the different PARP isoforms of interest was assessed in a displacement assay.

The identification of compounds capable of binding several PARP proteins is carried out through a screening method including the steps of

a) providing a reaction mixture containing:

the PARP protein isoform under investigation,

a compound of formula (IP):

wherein R₁₀ is hydrogen or methyl, B is (CH₂)_(n)NH group, n is 2 to 6; m is 0 or 1 and X⁻ is a counterion, and serial dilutions of the test compound; b) comparing the polarization signal generated in the absence of the test compound with the one generated in the presence of different concentrations of the test compound, and c) evaluating the ability of the test compound to displace the compound of formula (IP) as defined above indicated from a decreased fluorescence polarization level.

Preferably, for the screening method above cited, either the PARP protein and the 5H-Phenanthridin-6-one-derived probe of formula (IP) are pre-mixed, or the PARP protein and the test compound are pre-mixed. In a further preferred screening method, the PARP proteins are PARP-1, PARP-2 and PARP-3. The term “PARP protein” encompasses full-length native proteins as well as fragment thereof.

More preferably, R₁₀ is hydrogen or methyl, m is 0 or 1; when m is 1, n is 3 or 6, X⁻ is trifluoroacetate.

The 5H-phenanthridin-6-one-derived probe of the formula (IP) as described above was selected for its capability of binding to the PARP proteins, both encompassing full-length native proteins and fragment thereof.

The polarization signal can be measured, e.g., by a plate reader such as the Saphire2 (Tecan). The displacement ability of the test compound is in correlation with the compound affinity for the NAD pocket of the enzyme. Affinity binding constant (KD) and DC₅₀s of the test compound can be determined as explained in the Example section.

The assay of the invention is based on the use of known PARP inhibitors chemically conjugated to a moiety that provides the fluorescent signal. Specific compounds used in the present invention are:

-   P1.     9-Dimethylamino-11,11-dimethyl-1-(3-{methyl-[(6-oxo-5,6-dihydro-phenanthridin-2-ylcarbamoyl)-methyl]-carbamoyl}-propyl)-2,3,4,11-tetrahydro-naphtho[2,3-g]quinolinium     trifluoroacetate; -   P2.     9-dimethylamino-11,11-dimethyl-1-[3-(3-{[(6-oxo-5,6-dihydro-phenanthridin-2-ylcarbamoyl)-methyl]-amino}-propylcarbamoyl)-propyl]-2,3,4,11-tetrahydro-naphtho[2,3-g]quinolinium     trifluoroacetate; -   P3.     9-dimethylamino-11,11-dimethyl-1-[3-(6-{[(6-oxo-5,6-dihydro-phenanthridin-2-ylcarbamoyl)-methyl]-amino}-hexylcarbamoyl)-propyl]-2,3,4,11-tetrahydro-naphtho[2,3-g]quinolinium     trifluoroacetate.

The preparation of a compound of formula (IP) above described can be accomplished with a process including:

step i₀) either reacting a compound of formula (XVIII):

wherein Lg is a leaving group, preferably a chlorine atom, with a compound of formula (XIX): R₁₀—NH₂ wherein R₁₀ is as defined above, to give a compound of formula (XX):

wherein R₁₀ is as defined above and m is 0; or step i_(a)) reacting a compound of formula (XVIII) as defined above with a compound of formula XIXa:

wherein R₁₀ and B are as defined above, m is 1 and R₁₁ is hydrogen atom, methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl or the like; and step i_(b)) converting if necessary the resultant compound of formula (XXa):

wherein R₁₀ and B are as defined above, m is 1 and R₁₁ is a methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl group or the like, into a compound of formula (XX) as defined above; step ii) coupling the resultant compound of formula (XX) as defined above with a compound of formula (XXI):

wherein X⁻ is as defined above so as to obtain the final compound of formula (IP) as defined above; and, if necessary or wanted, converting a compound of formula (IP) into another compound of formula (IP) wherein X⁻ is different.

The starting compound of formula (XVIII) can be prepared as extensively described, for instance, in WO 2001042219; the compounds of formula (XXI) are described in Cha, J. H. et al., J. Med. Chem. 2005, 48, 7513-7516 and ATTO 610 fluorescent moiety activated as its NHS ester is commercially available (Naphtho[2,3-g]quinolinium, 9-(dimethylamino)-1-[4-[(2,5-dioxo-1-pyrrolidinyl)oxy]-4-oxobutyl]-2,3,4,11-tetrahydro-11,11-dimethyl-perchlorate (1:1), ATTO-TEC GmbH, Siegen, Germany).

Scheme 3 below shows the preparation of compound of formula (IP) wherein R₁₀, R₁₁, B and m have the meanings defined above.

According to steps i₀ and i_(a) of the process, a compound of formula (XVIII) as defined above is reacted with a compound of formula (XIX) or (XIXa) as defined above, in the presence of a base such as, for instance, sodium or potassium hydroxide, sodium, potassium or cesium carbonate, sodium or potassium hydrogencarbonate, triethylamine, N,N-diisopropylethylamine, pyridine and the like, in a suitable solvent such as acetonitrile, dioxane, methanol, ethanol or N,N-dimethylformamide at a temperature ranging from 0° C. to reflux to give, starting from compound (XIX), as defined above, a compound of formula (XX), as defined above, or, starting from compound (XIXa), as defined above, a compound of formula (XXa), as defined above;

According to step i_(b) of the process, a compound of formula (XXa) wherein m=1, R₁₁ is a methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl group or the like, is converted into a compound of formula (XX) as defined above by removing the corresponding nitrogen protective group. In particular, protective groups such as tert-butoxycarbonyl and the like can be removed under acidic conditions, preferably in the presence of an inorganic or organic acid such as hydrochloric, trifluoroacetic or methanesulphonic acid in a suitable solvent such as dichloromethane, dichloroethane, dioxane, a lower alcohol, such as methanol or ethanol, at a temperature ranging from room temperature to reflux. Protective groups such as benzyloxycarbonyl and the like can be removed with a suitable reducing agent, such as molecular hydrogen, cyclohexene, cyclohexadiene, formic acid, ammonium formate and the like in the presence of a hydrogenation catalyst, such as, for instance, palladium on carbon, palladium hydroxide, palladium black, Ni Raney and the like, in a suitable solvent, such as methanol, ethanol, dioxane and the like at a temperature ranging from room temperature to reflux. Protective groups such as methoxycarbonyl, ethoxycarbonyl, 9-fluorenylmethoxycarbonyl and the like could be removed under basic conditions such as, for instance, sodium, potassium or cesium carbonate, sodium, potassium or barium hydroxide, hydrazine, piperidine, morpholine and the like in a suitable solvent such as methanol, ethanol, water, N,N-dimethylformamide, N,N-dimethylacetamide and the like, at a temperature ranging from room temperature to reflux.

According to step ii of the process, a compound of formula (XX), as defined above, is reacted with a compound of formula (XXI) in the presence of a suitable base such as triethylamine, N,N-diisopropylethylamine, pyridine and the like, in a solvent such as N,N-dimethylformamide, N,N-dimethylacetamide and the like, at a temperature ranging from 0° C. to room temperature so as to obtain the desired compounds of formula (IP).

The assay is based on the use of a probe of formula (IP) that binds to the NAD binding pocket and takes advantage of the significant change in the polarization signal observed upon binding of the probe to PARP-1, -2 and -3.

The probe of formula (IP) was tested for its ability to bind FL PARP-1, -2 and -3 in a titration experiment. The assay performances were then evaluated (Z′ factor) as well as the displacement of the probe by its scaffold and known commercially available PARP inhibitors. In all of the experiments, the polarization signal was measured using a Saphire2 plate reader (Tecan). Data analysis was performed using Dynafit software. In particular, titration data were fitted to the following equilibria: Enzyme+probe <==> Complex Enzyme-probe, while displacement data were fitted to the following equilibria: Enzyme+probe <==> Complex Enzyme-probe, Enzyme+Compound <==> Complex Enzyme-Compound, whereby binding of probe and compound on the enzyme are mutually exclusive (pure competitive mechanism). Displacement data were also fitted using Excell spreadsheet (Microsoft Inc. Seattle, USA) to a four parameter logistic model (4PL), or Hill-Slope model to calculate DC₅₀s where the DC₅₀ value represents the compound concentration at which the polarization signal is diminished by 50% compared to untreated controls. The titration experiment was performed as follows: 50 nM probe (compound P1), FL PARP-1, -2 and -3 at concentrations from 5 μM to 0, with dilution steps 1:1.5 in 50 mM TrisHCl, pH 7.8, 150 mM sodium chloride, 10 mM magnesium chloride, 0.001% Triton X100, 1% DMSO (buffer 1). A similar procedure was used for compound P3 titration.

The obtained results, shown in Table 1 below, indicated that the probe (compound P1) is capable to bind all the tested isoforms of PARP. For compound P3 only PARP-1 KD is reported. The Z′ factor (Z′=1−(3*(SDprobe+protein+SDprobe)/(Meanprobe+protein−Meanprobe)) was determined as follows: 50 nM probe (compound P1), 250 nM of PARP-1 and -2, 200 nM of PARP-3. PARP-1 concentration was equal to 100 nM when compound P3 was used as probe. In all cases, the Z's were higher than 0.7 indicating that the assays were robust (table 1).

TABLE 1 KD (μM) STD (μM) Z′ PARP-1 FL (compound P3) 0.4 0.07 0.75 PARP-1 FL (compound P1) 1.04 0.14 0.73 PARP-2 FL (compound P1) 1.05 0.2 0.78 PARP-3 FL (compound P1) 0.18 0.016 0.9

The assay was validated using 3-aminobenzamide (3-AB) and PJ-34 (N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-N,N-dimethylacetamide) in a displacement assay performed as follows: serial dilutions of test compounds were first prepared in 100% DMSO and further diluted in assay buffer 1 in order to have a 1% final DMSO concentration. 3-AB were tested at 100 μM as highest concentration, while 10 μM was PJ-34 highest concentration. The enzymes were present at a final concentration of 250 nM for PARP-1 (100 nM when compound P3 was used as probe) and PARP-2 while 200 nM was used for PARP-3. Probe (compound P1 or compound P3) final concentration was 50 nM. The mixture of enzyme and probe (compound P1 or compound P3) was added to the previously diluted compounds. Results (Table 2) indicate that the probes (compound P1 or compound P3) could be fully displaced by 3-AB and PJ-34 from all of the tested PARP isoforms indicating that the probes (compound P1 or compound P3) binding is specific. In agreement, affinity binding constants (KD) were determined by fitting with a pure competitive mechanism. KD values, are the average of three independent experiments.

3-AB, as expected, was not selective among the PARP isoforms and showed a lower affinity with respect to PJ-34.

TABLE 2 PJ34 KD STD 3-AB KD STD (μM) (μM) (μM) (μM) PARP-1 FL (compound P3) <0.01* 5.56 0.55 PARP-1 FL (compound P1) <0.03* 6.68 1.2 PARP-2 FL (compound P1) <0.03* 7.4 1.04 PARP-3 FL (compound P1) 0.15 0.026 17.7 4.25 *assay sensitivity limits based on a fitting error <50%

Taken together, these results show that the displacement assay is specific. Moreover it allows quantitative potency evaluation of standard PARP inhibitors tested, and therefore selectivity evaluation among assays.

The same assay, by using either probe P1 or P3, was used to evaluate compounds of formula (I) reported in table 3.

TABLE 3 PARP-2 PARP-3 PARP-1 (DC₅₀ (DC₅₀ PAR assay Compound (DC₅₀ μM) (Kd μM) μM) μM) IC₅₀ (μM) 1 <0.25 0.06* >10 3.7 0.39 2 <0.25 0.025* >10 6 0.16 3 <0.25 0.013** >10 2.3 0.14 4 <0.25 0.02* >10 4.9 0.09 5 <0.25 0.04 >10 — 4.60 6 <0.25 <0.03 >10 — 2.30 7 <0.25 <0.01* 3 3.54 0.33 8 0.28 0.13 >10 >10 0.53 10 <0.25 0.04 >10 — 6.60 11 <0.25 0.04 >10 — 3.95 12 <0.25 <0.03 >10 — — 13 <0.25 <0.03 >10 — — 14 <0.25 0.066 >10 — 1.56 15 <0.25 0.05 >10 — — 16 <0.25 <0.03 3.20 — — 17 <0.25 <0.03 >10 — 5.77 18 <0.25 <0.03 >10 — 7.10 19 <0.25 0.04 >10 — 1.10 21 <0.25 0.05 3.84 — 4.42 22 <0.25 <0.03 5.5 — 5.99 23 <0.25 0.05 >10 — 3.00 25 <0.25 <0.03 >10 — 9.89 26 <0.25 <0.03 6.5 — 0.20 27 0.26 <0.03 >10 — 0.32 28 <0.25 0.034 6.76 — 0.19 29 <0.25 <0.03 4.65 — 0.10 30 <0.25 — 5.97 — 0.30 31 <0.25 <0.03 >10 — 0.11 32 <0.25 0.04* >10 0.27 0.38 33 <0.25 — >10 — 1.10 34 0.34 0.13 >10 — 0.90 35 <0.25 <0.03 >10 — 0.30 36 <0.25 <0.03 9.4 — 0.23 37 <0.25 <0.03 >10 — 0.26 38 <0.25 <0.03 >10 — 0.26 39 <0.25 <0.03 >10 — 0.33 40 <0.25 0.11 >10 — 0.62 41 0.47 >10 — — 42 <0.25 0.033 4.15 — 5.31 43 <0.25 <0.03 >10 — 2.66 44 <0.25 — >10 — 0.50 45 <0.25 <0.03 >10 — 0.36 46 <0.25 1.46 — 0.40 47 <0.25 <0.03 3.13 — 0.08 49 <0.25 2.35 — 0.04 51 <0.25 <0.03 5.68 — 0.16 99 <0.25 <0.01* 2.54 1.58 0.01 100 <0.25 <0.01* >10 0.79 0.50 101 <0.25 0.08* >10 >10 1.9  103 <0.25 <0.01* 3.77 4.67 0.08 105 <0.25 <0.01* >10 1.08 0.08 106 0.28 0.11 >10 2.55 0.41 *Assay performed with compound P3 as the probe. In all other cases compound P1 was used as the probe. From the data above it is clear that compounds of formula (I) of the present invention are highly potent as PARP-1 inhibitors and extremely selective versus PARP-2 and PARP-3 (compare PARP-1 Kd, PARP-2 DC₅₀ and PARP-3 DC₅₀ values in the table 3 above). Pharmacology

Compounds potencies were evaluated by measuring the inhibition of poly (ADP-ribose) (PAR) chains formation as a marker for PARP-1 inhibition.

PARP-1 is a DNA damage-induced polymerase that catalyzes the cleavage of NAD+ into nicotinamide and ADP-ribose and then uses the latter to synthesize branched nucleic-acid like polymers poly(ADP-ribose). In vivo, the most abundantly poly (ADP-ribosylated) protein is PARP-1 itself, followed by histones. PARP-1 is responsible for 90% of this DNA damage-induced activity while the remaining 10% is due to PARP-2.

Cellular Assay

Cellular activity of PARP-1 inhibitors was assessed by measuring the inhibition of the hydrogen peroxide induced PAR formation in HeLa cells (ECACC). Cellular PAR levels were measured by immunocytochemistry, and quantified using an ArrayScan vTi instrument (Cellomics Thermo Scientific).

Studies were performed as follows: 6000 cells/well were seeded in 96 well plates (Perkin Elmer) in MEM/10% FCS and incubated for 24 hours at 37° C., 5% carbon dioxide. Test compounds were then added at the required concentration for 30′. DNA damage was then induced adding hydrogen peroxide at the concentration of 0.1 mM for 15 min. Concentration curves were prepared in MEM/10% FCS from compound stocks in DMSO, and final DMSO concentration was 0.002% (v/v). Duplicate wells for each concentration point were prepared with a typical highest compound concentration of 20 μM and serial dilution 1:3. Plates were dried and fixed adding cold methanol-acetone (70:30) solution for 15 min at room temperature, fixing solution was aspired and wells were air dried for 5 min and then dehydrated in PBS. Non-specific binding sites were blocked by incubating wells for 30 min in PBS containing 5% (w/v) FBS 0.05% tween20. Wells were then incubated for 1 hour at room temperature in PBS containing anti PAR mouse monoclonal antibody (Anti-PAR, Mouse mAb 10H, Tulip Cat No 1020) diluted 1:200 in blocking solution. After 3 washes in PBS, wells are incubated in PBS (w/v) 5% FBS 0.05% Tween20 containing 2 μg/mL Cy2-conjugated Goat anti mouse secondary antibody (Amersham Pharmacia Biotech cat. No PA 42002) (Absorption maximum 489 nm fluorescence maximum 506 nm) and 1 μg/mL DAPI (Absorption maximum 359 nm fluorescence maximum 461 nm) (4′,6-Diamidino-2-phenylndole dilactate) (Sigma cat. No D9564), a high sensitivity dye for nucleic acid staining. After washing further 3 times in PBS, cellular PAR immunoreactivity was assessed using the ArrayScan vTi instrument, with a Zeiss 10×0.5 N.A. objective, and applying the Cytotoxicity.V3 algorithm (Cellomics/Thermo Fisher) with a XF100 filter. At least 10 fields, corresponding to at least 900 cells, were read for each well. IC₅₀ values represent the compound concentration at which cellular PAR signal is diminished by 50% compared with untreated controls.

The following formula is used: IC₅₀=Bottom+(Top-Bottom)/(1+10^((LogEC50−X))); X is the logarithm of concentration. IC₅₀ is the response; IC₅₀ starts at Bottom and goes to Top with a sigmoid shape.

Given the above assays, compounds of formula (I) of the present invention inhibited PAR formation with IC₅₀ values lower than 10 μM, as it is shown in the right end column of table 3 above.

Pharmacokinetics

The pharmacokinetic profile and the oral bioavailability of the compounds have been investigated in the mouse (Balb, Nu/Nu, Harlan, Italy) in ad hoc pharmacokinetic studies. The compounds were formulated in 10% tween 80/dextrose for intravenous bolus administration while oral administrations were performed using the compounds formulated in 0.5% methylcellulose. A single administration at the dose of 10 mg/kg was given and three male animals for each route were used. All blood samples were taken from saphenous vein at 5 min, 30 min, 1 hour, 6 hours, 24 hours after intravenous administration and 15 min, 30 min, 1 hour, 6 hours, 24 hours after oral administration. Plasma samples were prepared by plasma proteins precipitation adding 200 μL of methanol to 10 μL of plasma in a 96 well plate. After capping and vortex mixing, the plate was centrifuged for 15 min at 3700 rpm at 6° C. The supernatant was considered as final extract and injected onto the LC-MS-MS system (HPLC system: Hewlett Packard 1100 series using Atlantis HILIC Silica 50*2.1 mm 5.0 μm analytical column; MS instrument: Perkin Elmer SCIEX API 2000 and ionization performed with Turbo Ion Spray in positive ion mode). Lower limit of quantification is 5.0 ng/mL, upper limit of quantification is 10000 ng/mL. Analysis was performed using the Watson package (version 6.4.0.04) and Excel spreadsheet (Microsoft Inc. Seattle, USA). Non-compartmental method (linear trapezoidal rule and linear regression analysis of natural log-transformed plasma concentrations vs. time data) was used. After intravenous dosing, C₀ was set equal to C_(0.083) Absolute bioavailability (F) was calculated from the ratio of average oral to IV (intravenous) dose-normalized plasma AUC (area under curve) values.

Some representative compounds of formula (I) were evaluated for their pharmacokinetic parameters as reported in table 4 as mean value.

TABLE 4 CL (IV Vdss bolus) (IV AUC (oral) C-max T½ mL/ bolus) 0-24 h (oral) (oral) F on Compounds min/kg L/Kg μM · hours μM hours AUC % 3 103.6 4.75 2.39 1.17 1.75 82.5 4 134.7 5.95 1.3 0.4 1.42 55 7 17 3.4 20.9 3.62 2.9 80 29 110 4.86 3.45 1 1.67 85 32 59.5 2.78 1.48 0.43 1.84 24 99 19 3.9 19.6 5.24 3.1 95

From the above, it is clear to the person skilled in the art that compounds of formula (I) possess good to excellent pharmacokinetics profiles and oral bioavailability.

In Vivo Efficacy Studies

Balb, athymic Nu/Nu male mice, from Harlan (Italy), were maintained in agreement with the European Communities Council Directive no. 86/609/EEC concerning the protection of animals used for experimental or other scientific purposes, in cages with paper filter cover, food and bedding sterilized and acidified water. Fragments of Capan-1 human pancreatic cancer tumors were implanted subcutaneously. Mice bearing a palpable tumor (100-200 mm³) were selected and randomized into control and treated groups. Each group included seven animals. The treatment started one day after randomization. Compound of formula (I) was administered by oral route as a methocel suspension at the indicated doses and times. Tumor dimension was measured regularly by calipers during the experiments and tumor mass was calculated as described in Simeoni M. et al., Cancer Res 64, 1094-1101 (2004). The tumor growth inhibition (TGI, %) was calculated according to the equation: % TGI=100-(mean tumor weight of treated group/mean tumor weight of control group)*100.

Some representative compounds of formula (I), were evaluated for their anti-tumor activity as single agent on Capan-1 BRCA-2 mutated mouse model and results are reported in table 5. Toxicity was evaluated on the basis of body weight reduction (no body weight reduction observed out of 7 mice treated).

TABLE 5 Compounds Dose Schedule Max TGI (%) Toxicity 7  80 mg/kg 1-8 daily 47% 0/7 29 100 mg/kg 1-14 daily 38% 0/7 32 100 mg/kg 1-6 twice a day 32% 0/7 99 100 mg/kg 1-15 daily 55% 0/7

Therefore, the present invention provides compounds of formula (I) useful in therapy.

Compounds of formula (I) of the present invention, suitable for administration to a mammal, e.g., to humans, can be administered by the usual routes and the dosage level depends upon the age, weight, conditions of the patient and administration route.

For example, a suitable dosage adopted for oral administration of a compound of formula (I) may range from about 1 to about 1000 mg per dose, from 1 to 5 times daily. The compounds of the invention can be administered in a variety of dosage forms, e.g., orally, in the form tablets, capsules, sugar or film coated tablets, liquid solutions or suspensions; rectally in the form suppositories; parenterally, e.g., intramuscularly, or through intravenous and/or intrathecal and/or intraspinal injection or infusion.

As stated above, the present invention also includes pharmaceutical compositions comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof in association with a pharmaceutically acceptable excipient, which may be a carrier or a diluent.

The pharmaceutical compositions containing the compounds of the invention are usually prepared following conventional methods and are administered in a suitable pharmaceutical form. For example, the solid oral forms may contain, together with the active compound, diluents, e.g., lactose, dextrose saccharose, sucrose, cellulose, corn starch or potato starch; lubricants, e.g., silica, talc, stearic acid, magnesium or calcium stearate, and/or polyethylene glycols; binding agents, e.g., starches, arabic gum, gelatine methylcellulose, carboxymethylcellulose or polyvinyl pyrrolidone; disintegrating agents, e.g., starch, alginic acid, alginates or sodium starch glycolate; effervescing mixtures; dyestuffs; sweeteners; wetting agents such as lecithin, polysorbates, laurylsulphates; and, in general, non-toxic and pharmacologically inactive substances used in pharmaceutical formulations. These pharmaceutical preparations may be manufactured in known manner, for example, by means of mixing, granulating, tabletting, sugar-coating, or film-coating processes.

The liquid dispersions for oral administration may be, e.g., syrups, emulsions and suspensions. As an example, the syrups may contain, as carrier, saccharose or saccharose with glycerine and/or mannitol and sorbitol.

The suspensions and the emulsions may contain, as examples of carriers, natural gum, agar, sodium alginate, pectin, methylcellulose, carboxymethylcellulose, or polyvinyl alcohol. The suspension or solutions for intramuscular injections may contain, together with the active compound, a pharmaceutically acceptable carrier, e.g., sterile water, olive oil, ethyl oleate, glycols, e.g., propylene glycol and, if desired, a suitable amount of lidocaine hydrochloride.

The solutions for intravenous injections or infusions may contain, as a carrier, sterile water or preferably they may be in the form of sterile, aqueous, isotonic, saline solutions or they may contain propylene glycol as a carrier.

The suppositories may contain, together with the active compound, a pharmaceutically acceptable carrier, e.g., cocoa butter, polyethylene glycol, a polyoxyethylene sorbitan fatty acid ester surfactant or lecithin.

EXPERIMENTAL SECTION

For a reference to any specific compound of formula (I) of the invention, optionally in the form of a pharmaceutically acceptable salt, see the experimental section and claims. Referring to the examples that follow, compounds of the present invention were synthesized using the methods described herein, or other methods, which are well known in the art.

The short forms and abbreviations used herein have the following meaning:

-   μM (micromolar) -   μL (microliter) -   μm (micrometer) -   mol (moles) -   mM (millimolar) -   mmol (millimoles) -   g (grams) -   mg (milligrams) -   DC₅₀ (the half maximal Displacement Concentration) -   IC₅₀ (the half maximal Inhibitory Concentration) -   STD (Standard Deviation) -   PAR (poly (ADP-ribose)) -   MEM (Minimal Essential Medium) -   FCS (Fetal Calf Serum) -   FBS (Fetal Bovine Serum) -   PBS (Phosphate Buffered Saline) -   LC-MS (Liquid Chromatography-Mass Spectrometry) -   HPLC (High Performance Liquid Chromatography) -   AUC (area under the plasma concentration vs. time curve up to the     last detectable concentration) -   Cl (plasma clearance) -   Cmax (maximum plasma concentration) -   T1/2 (terminal half life) -   Vdss (volume of distribution at steady state) -   TGI (Tumor Growth Inhibition) -   MHz (megahertz) -   Hz (Hertz) -   DMSO (dimethylsulfoxide) -   ESI (electrospray ionization)

With the aim to better illustrate the present invention, without posing any limitation to it, the following examples are now given.

As used herein the symbols and conventions used in the processes, schemes and examples are consistent with those used in the contemporary scientific literature, for example, the Journal of the American Chemical Society or the Journal of Biological Chemistry.

Unless otherwise noted, all materials were obtained from commercial suppliers, of the best grade and used without further purification. Anhydrous solvent such as N,N-dimethylformamide, tetrahydrofuran, dichloromethane and toluene were obtained from the Aldrich Chemical Company. All reactions involving air- or moisture-sensitive compounds were performed under nitrogen or argon atmosphere.

General Purification and Analytical Methods

Flash Chromatography was performed on silica gel (Merck grade 9395, 60A). HPLC was performed on Waters X Terra RP 18 (4.6×50 mm, 3.5 μm) column using a Waters 2790 HPLC system equipped with a 996 Waters PDA detector and Micromass mod. ZQ single quadrupole mass spectrometer, equipped with an electrospray (ESI) ion source. Mobile phase A was ammonium acetate 5 mM buffer (pH 5.5 with acetic acid-acetonitrile 95:5), and mobile phase B was water-acetonitrile (5:95). Gradient from 10 to 90% B in 8 minutes, hold 90% B 2 minutes. UV detection at 220 nm and 254 nm. Flow rate 1 mL/min. Injection volume 10 μL. Full scan, mass range from 100 to 800 amu. Capillary voltage was 2.5 KV; source temperature was 120° C.; cone was 10 V. Retention times (HPLC r.t.) are given in minutes at 220 nm or at 254 nm. Mass are given as m/z ratio.

When necessary, compounds were purified by preparative HPLC/MS by using Waters FractionLynx System LC, equipped with UV-VIS detector Waters 2996 PDA and MS detector Waters ZQ™ (single quadrupole), equipped with an electrospray (ESI +/−) ion source. Column was Waters X Terra RP 18 (30×150 mm, 5 μm, 19×100 mm). Mobile phase A was water-0.01% trifluoroacetic acid, and mobile phase B was acetonitrile. Gradient from 10 to 90% B in 8 min, hold 90% B 2 min. Flow rate 20 mL/min. In alternative, mobile phase A was 0.05% ammonium hydroxide pH10/acetonitrile 95/5 and mobile phase B was acetonitrile. Gradient: from 0% to 50% B in 20 minutes, then to 100% B in 0.1 minute. Flow rate 20 mL/min. Mass are given as m/z ratio. Full scan, mass range from 100 to 1200 amu. Capillary voltage was 3.25 kV (ES+) and 2.75 kV (ES−). Source temperature was 120° C. Cone Voltage was 18 V (ES+) and 18 V (ES−)

1H-NMR spectrometry was performed on a Mercury VX 400 operating at 400.45 MHz equipped with a 5 mm double resonance probe [1H (15N-31P) ID_PFG Varian].

Example 1 Step l 4-[(Furan-2-ylmethyl)-amino]-piperidine-1-carboxylic acid tert-butyl ester

To an equimolar solution of furan-2-carbaldehyde (250 mg, 2.6 mmol) and 4-amino-piperidine-1-carboxylic acid tert-butyl ester (473 mg, 2.6 mmol) in dichloromethane (14 mL) 1M titanium(IV) chloride in dichloromethane (1.3 mL, 1.3 mmol) and triethylamine (0.32 mL, 2.6 mmol) were added. The reaction mixture was stirred under nitrogen atmosphere for 2 days. Then sodium cyanoborohydride (493 mg, 7.8 mmol) in methanol (7 mL) was added dropwise with stirring and the solution was allowed to stir overnight at room temperature. 35% Sodium hydroxide was added and the product was extracted with ethyl acetate. The solvent was removed under reduce pressure and the crude was purified by flash chromatography (dichloromethane/methanol 95:5) to give the title compound as a red oil (406 mg, 56%).

ESI(+) MS: m/z 281 (MH⁺).

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained:

Furan-2-ylmethyl-(2-methoxy-ethyl)-amine

ESI(+) MS: m/z 156 (MH⁺).

{3-[4-(3-Chloro-phenyl)-piperazin-1-yl]-propyl}-furan-2-ylmethyl-amine

ESI(+) MS: m/z 334 (MH⁺).

4-{[(Furan-2-ylmethyl)-amino]-methyl}-piperidine-1-carboxylic acid tert-butyl ester

ESI(+) MS: m/z 295 (MH⁺).

{3-[(Furan-2-ylmethyl)-amino]-propyl}-carbamic acid tert-butyl ester

ESI(+) MS: m/z 255 (MH⁺).

Ethyl N-(furan-2-ylmethyl)glycinate

ESI(+) MS: m/z 184 (MH⁺).

Step m 3-(1-Tert-butoxycarbonyl-piperidin-4-yl)-4-oxo-10-oxa-3-aza tricyclo[5.2.1.0*1,5*]dec-8-ene-6-carboxylic acid

To a solution of 4-[(furan-2-ylmethyl)-amino]-piperidine-1-carboxylic acid tert-butyl ester (5.6 g, 21 mmol) in toluene (300 mL) maleic anhydride (2.1 g, 21 mmol) was added. The reaction mixture was refluxed for 6 hours and stirred overnight at room temperature. The precipitate solid obtained was filtered, washed with diethyl ether and dried to give the desired compound (6.5 g, 82%) as a white solid.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.40 (s, 9H) 1.57-1.67 (m, 1H) 2.45 (d, J=9.28 Hz, 1H) 2.76 (br. s., 2H) 2.76 (d, J=9.28 Hz, 1H) 3.59 (d, J=11.47 Hz, 1H) 3.90 (tt, J=7.60, 4.30 Hz, 0H) 3.88 (d, J=11.60 Hz, 1H) 4.01 (d, J=12.33 Hz, 2H) 4.95 (d, J=1.59 Hz, 1H) 6.42 (dd, J=5.61, 1.71 Hz, 1H) 6.55 (d, J=5.74 Hz, 1H) 12.03 (br. s., 1H).

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained:

3-(2-Methoxy-ethyl)-4-oxo-10-oxa-3-aza-tricyclo[5.2.1.0*1,5*]dec-8-ene-6-carboxylic acid

ESI(+) MS: m/z 254 (MH⁺).

3-{3-[4-(3-Chloro-phenyl)-piperazin-1-yl]-propyl}-4-oxo-10-oxa-3-aza-tricyclo[5.2.1.0*1,5*]dec-8-ene-6-carboxylic acid

ESI(+) MS: m/z 432 (MH⁺).

3-(1-Tert-butoxycarbonyl-piperidin-4-ylmethyl)-4-oxo-10-oxa-3-aza-tricyclo[5.2.1.0*1,5*]dec-8-ene-6-carboxylic acid

ESI(+) MS: m/z 393 (MH⁺).

3-(3-Tert-butoxycarbonylamino-propyl)-4-oxo-10-oxa-3-aza-tricyclo[5.2.1.0*1,5*]dec-8-ene-6-carboxylic acid

ESI(+) MS: m/z 353 (MH⁺).

2-(2-Ethoxy-2-oxoethyl)-1-oxo-1,2,3,6,7,7a-hexahydro-3a,6-epoxyisoindole-7-carboxylic acid

ESI(+) MS: m/z 282 (MH⁺).

Step n 3-Oxo-2-piperidin-4-yl-2,3-dihydro-1H-isoindole-4-carboxylic acid

3-(1-Tert-butoxycarbonyl-piperidin-4-yl)-4-oxo-10-oxa-3-aza-tricyclo[5.2.1.0*1,5*]dec-8-ene-6-carboxylic acid (6.35 g, 16.8 mmol) was dissolved in 37% hydrochloric acid (80 mL) and the resulted solution was refluxed for 3 hours. The solvent was removed under reduced pressure and the residue was diluted with methanol and decanted in order to obtained the desired product as a white solid (4.06 g, 82%).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.95-2.12 (m, 4H) 3.01-3.18 (m, 2H) 3.41 (d, J=12.57 Hz, 2H) 4.42 (dt, J=15.62, 8.06 Hz, 1H) 4.72 (s, 2H) 7.85 (t, J=7.70 Hz, 1H) 7.95 (dd, J=7.63, 0.79 Hz, 1H) 8.17 (dd, J=7.75, 0.79 Hz, 1H) 8.38-8.66 (m, 1H) 8.79 (d, J=10.38 Hz, 1H) 15.86 (s, 1H).

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained:

2-(2-Methoxy-ethyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid

ESI(+) MS: m/z 236 (MH⁺).

2-{3-[4-(3-Chloro-phenyl)-piperazin-1-yl]-propyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid

ESI(+) MS: m/z 414 (MH⁺).

3-Oxo-2-piperidin-4-ylmethyl-2,3-dihydro-1H-isoindole-4-carboxylic acid

ESI(+) MS: m/z 275 (MH⁺).

2-(3-Amino-propyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid

ESI(+) MS: m/z 235 (MH⁺).

2-(2-Ethoxy-2-oxoethyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid

ESI(+) MS: m/z 264 (MH⁺).

Conversion 1 2-(1-Tert-butoxycarbonyl-piperidin-4-yl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid

To a solution of 3-oxo-2-piperidin-4-yl-2,3-dihydro-1H-isoindole-4-carboxylic acid (3.9 g, 13.2 mmol) in pyridine (15 mL) potassium carbonate (3.6 g, 26.5 mol) and methanol (40 mL) were successively added. Then di-tert-butyl dicarbonate (3.16 g, 14.5 mmol) was added and the reaction mixture was stirred at room temperature for 4 hours until HPLC analysis revealed the disappearance of the starting material. The solvent was removed under reduced pressure and the residue was dissolved in dichloromethane. The solution was washed twice with 5% potassium hydrogen sulfate and the organic phase was dried over anhydrous sodium sulfate and concentrated in vacuo. The obtained crude wad diluted with diethyl ether and decanted to obtain the title compound (3.7 g, 78%) as a white solid. ¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.42 (s, 9H) 1.69 (qd, J=12.35, 4.58 Hz, 2H) 1.85 (dq, J=12.77, 2.40 Hz, 2H) 2.89 (br. s., 2H) 4.08 (d, J=12.69 Hz, 2H) 4.28 (tt, J=11.86, 3.95 Hz, 1H) 4.73 (s, 2H) 7.79-7.86 (m, 1H) 7.88-7.93 (m, 1H) 8.17 (dd, J=7.69, 0.85 Hz, 1H) 16.03 (br. s., 1H).

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained:

2-(1-Tert-butoxycarbonyl-piperidin-4-ylmethyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid

ESI(+) MS: m/z 375 (MH⁺).

2-(3-Tert-butoxycarbonylamino-propyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid

ESI(+) MS: m/z 335 (MH⁺).

Step o 4-(7-Carbamoyl-1-oxo-1,3-dihydro-isoindol-2-yl)-piperidine-1-carboxylic acid tert-butyl ester

To a solution of 2-(1-tert-butoxycarbonyl-piperidin-4-yl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid (3.7 g, 10.3 mmol) in N,N-dimethylformamide (60 mL) hydroxybenzotriazole ammonium salt (3.15 g, 20.7 mmol), 1-ethyl-3-(3′-dimethylamino) carbodiimide hydrochloric acid salt (3.34 g, 20.7 mmol) and diisopropylethylamine (5.3 mL, 30.9 mmol) were added. The reaction mixture was stirred at room temperature overnight. The solvent was removed under reduce pressure and the residue was dissolved in ethyl acetate. The solution was washed twice with saturated sodium carbonate aqueous solution, and the organic phase was dried over anhydrous sodium sulfate and concentrated in vacuo. The crude was purified by flash chromatography (dichloromethane/methanol 97:3) to afford the title compound (2.74 g, 74%) as a white solid.

ESI(+) MS: m/z 360 (MH⁺).

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained:

2-(2-Methoxy-ethyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid amide, cpd 9

¹H NMR (400 MHz, DMSO-d₆) δ ppm 3.28 (s, 3H) 3.60 (t, J=5.37 Hz, 2H) 3.75 (t, J=5.30 Hz, 2H) 4.61 (s, 2H) 7.67 (br. s., 1H) 7.72 (t, J=7.56 Hz, 1H) 7.77 (dd, J=7.56, 1.30 Hz, 1H) 8.20 (dd, J=7.56, 1.34 Hz, 1H) 10.68 (br. s., 1H).

2-{3-[4-(3-Chloro-phenyl)-piperazin-1-yl]-propyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid amide, cpd 46

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.09 (tt, J=7.70, 7.00 Hz, 2H) 3.68 (t, J=6.59 Hz, 2H) 4.60 (s, 2H) 6.87 (dd, J=7.81, 1.34 Hz, 1H) 6.96 (d, J=8.42 Hz, 1H) 7.05 (t, J=2.14 Hz, 1H) 7.26 (t, J=8.18 Hz, 1H) 7.68 (d, J=1.22 Hz, 1H) 7.71 (br. s., 1H) 7.75 (t, J=7.57 Hz, 1H) 7.81 (dd, J=7.45, 1.10 Hz, 1H) 8.21 (dd, J=7.63, 1.16 Hz, 1H) 9.05 (s, 1H) 10.59 (br. s., 1H).

4-(7-Carbamoyl-1-oxo-1,3-dihydro-isoindol-2-ylmethyl)-piperidine-1-carboxylic acid tert-butyl ester

ESI(+) MS: m/z 374 (MH⁺).

3-(7-Carbamoyl-1-oxo-1,3-dihydro-isoindol-2-yl)-propyl]-carbamic acid tert-butyl ester

ESI(+) MS: m/z 334 (MH⁺).

Ethyl (7-carbamoyl-1-oxo-1,3-dihydro-2H-isoindol-2-yl)acetate

ESI(+) MS: m/z 263 (MH⁺).

Conversion 2 3-Oxo-2-piperidin-4-yl-2,3-dihydro-1H-isoindole-4-carboxylic acid amide

A solution of tert-butyl-4-(4-carbamoyl-1-methyl-3-oxo-1,3-dihydro-2H-isoindol-2-yl)piperidine-1-carboxylate (2.7 g, 7.5 mmol) in 4M hydrochloric acid in dioxane (18 mL, 75 mmol) was stirred at 50° C. for 2 hours until HPLC analysis revealed the disappearance of the starting material. The solvent was removed under reduce pressure and the product was dissolved in diethyl ether and filtered to obtain the title compound (2.09 g, 95%) as its hydrochloride.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.93-2.09 (m, 4H) 3.03-3.17 (m, 2H) 3.43 (br. s., 2H) 4.32-4.45 (m, 1H) 4.56 (s, 2H) 7.71 (br. s., 1H) 7.75 (t, J=7.56 Hz, 1H) 7.80-7.83 (m, 1H) 8.21 (dd, J=7.62, 1.16 Hz, 1H) 8.52-8.68 (m, 1H) 8.82 (d, J=9.51 Hz, 1H) 10.58 (br. s., 1H).

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained:

3-Oxo-2-piperidin-4-ylmethyl-2,3-dihydro-1H-isoindole-4-carboxylic acid amide

ESI(+) MS: m/z 274 (MH⁺).

2-(3-Amino-propyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid amide

ESI(+) MS: m/z 234 (MH⁺).

Conversion 3 2-[1-(4,4-Difluorocyclohexyl)-piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid amide, cpd 7

To a suspension of 3-oxo-2-piperidin-4-yl-2,3-dihydro-1H-isoindole-4-carboxylic acid amide (56 mg, 0.19 mmol) in dichloromethane (2 mL) 4,4-difluorocyclohexanone (37.5 mg, 0.28 mmol) sodium acetate (32 mg, 0.38 mmol) and methanol (0.3 mL) were added. The resulted solution was stirred at room temperature for 5 hours. Then sodium cyanoborohydride was added and the mixture was stirred overnight. Solvents were removed under reduce pressure and the residue was dissolved in dichloromethane and washed twice with water. The organic phase was dried over anhydrous sodium sulfate and concentrated in vacuo and the residue was purified by flash chromatography (dichloromethane/methanol: 95:5) to give the title compound.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.56 (br. s., 2H) 2.22-2.36 (m, 2H) 2.46-2.54 (m, 1H) 2.94 (br. s., 2H) 4.03 (br. s., 1H) 4.55 (s, 2H) 7.66 (br. s., 1H) 7.69-7.74 (m, 1H) 7.74-7.78 (m, 1H) 8.20 (dd, J=7.45, 1.46 Hz, 1H) 10.73 (br. s., 1H).

Example 2

Operating in an analogous way to that described in the previous example, but employing suitably substituted starting material, the following compounds were obtained:

2-[1-(Cis-4-methoxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 1

Cis-stereoisomer has been obtained by preparative HPLC/MS by using Waters FractionLynx System LC, equipped with UV-VIS detector Waters 2996 PDA and MS detector Waters ZQ™ (single quadrupole), equipped with an electrospray (ESI +/−) ion source and with Waters Xterra Prep RP18, 5 μm, 19×250 mm as column system and 0.05% ammonium hydroxide pH10/acetonitrile 95/5 as mobile phase A and acetonitrile as mobile phase B. LC conditions: gradient from 0% to 50% B in 20 minutes, then to 100% B in 0.1 minute. Flow rate 20 ml/min.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.29-1.42 (m, 194H) 1.81-1.99 (m, 193H) 2.15-2.43 (m, 33H) 2.78-3.01 (m, 190H) 3.16-3.23 (m, 3H) 4.00 (t, J=5.43 Hz, 95H) 4.55 (s, 188H) 7.66 (br. s., 79H) 7.68-7.74 (m, 113H) 7.74-7.78 (m, 94H) 8.20 (dd, J=7.45, 1.46 Hz, 96H) 10.74 (br. s., 92H).

2-[1-(Trans-4-methoxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 2

Trans-stereoisomer has been obtained by preparative HPLC/MS by using Waters FractionLynx System LC, equipped with UV-VIS detector Waters 2996 PDA and MS detector Waters ZQ™ (single quadrupole), equipped with an electrospray (ESI +/−) ion source and with Waters Xterra Prep RP18, 5 μm, 19×250 mm as column system and 0.05% ammonium hydroxide pH10/acetonitrile 95/5 as mobile phase A and acetonitrile as mobile phase B. LC conditions: gradient from 0% to 50% B in 20 minutes, then to 100% B in 0.1 minute. Flow rate 20 ml/min.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.01-1.18 (m, 2H) 1.89-2.12 (m, 2H) 2.17-2.42 (m, 3H) 2.82-2.98 (m, 2H) 2.98-3.12 (m, 1H) 3.22 (s, 3H) 3.85-4.13 (m, 1H) 4.54 (s, 2H) 7.66 (br. s., 1H) 7.68-7.74 (m, 1H) 7.74-7.78 (m, 1H) 8.20 (dd, J=7.51, 1.40 Hz, 1H) 10.74 (br. s., 1H).

2-{1-[Cis-4-(hydroxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 3

Compound 3 was obtained operating in analogous way as for cpd 1.

ESI(+) MS: m/z 372 (MH⁺).

2-{1-[Trans-4-(hydroxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 4

Compound 4 was obtained operating in analogous way as for cpd 2.

ESI(+) MS: m/z 372 (MH⁺).

2-{1-[Cis-4-(methoxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 5

Compound 5 was obtained operating in analogous way as for cpd 1.

ESI(+) MS: m/z 386 (MH⁺).

2-{1-[Trans-4-(methoxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 6

Compound 6 was obtained operating in analogous way as for cpd 2.

ESI(+) MS: m/z 386 (MH⁺).

2-[1-(1,4-Dioxaspiro[4.5]dec-8-yl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 8

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.93 (d, J=11.47 Hz, 2H) 3.93-4.08 (m, 1H) 4.55 (s, 2H) 7.66 (br. s., 1H) 7.71 (t, J=7.51 Hz, 1H) 7.76 (dd, J=7.51, 1.20 Hz, 1H) 8.20 (dd, J=7.45, 1.46 Hz, 1H) 10.74 (br. s., 1H).

2-{1-[4-(Dimethylamino)benzyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 10

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.77 (br. s., 4H) 2.02 (t, J=11.04 Hz, 2H) 2.82 (s, 6H) 2.91 (d, J=12.40 Hz, 2H) 3.36 (br. s., 2H) 4.04 (br. s., 1H) 4.55 (s, 2H) 6.69 (d, J=8.41 Hz, 2H) 7.11 (d, J=7.80 Hz, 2H) 7.66 (br. s., 1H) 7.71 (t, J=7.50 Hz, 1H) 7.76 (dd, J=7.56, 1.20 Hz, 1H) 8.19 (dd, J=7.50, 1.40 Hz, 1H) 10.72 (br. s., 1H).

2-[1-(4-Fluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 11

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.68-1.89 (m, 4H) 2.09 (t, J=11.16 Hz, 2H) 2.91 (d, J=10.49 Hz, 2H) 3.49 (s, 2H) 4.06 (br. s., J=11.00, 11.00, 4.50, 4.50 Hz, 1H) 4.56 (s, 2H) 7.15 (t, J=8.78 Hz, 2H) 7.36 (dd, J=7.80, 5.98 Hz, 2H) 7.66 (br. s., 1H) 7.71 (t, J=7.50 Hz, 1H) 7.76 (dd, J=7.56, 1.30 Hz, 1H) 8.20 (dd, J=7.44, 1.46 Hz, 1H) 10.71 (br. s., 1H).

2-[1-(2-Fluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 12

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.77 (d, J=11.80 Hz, 2H) 1.82 (qd, J=11.80, 3.20 Hz, 2H) 2.15 (td, J=11.25, 2.74 Hz, 2H) 2.95 (d, J=11.34 Hz, 2H) 3.58 (s, 2H) 4.05 (tt, J=11.50, 4.50 Hz, 1H) 4.57 (s, 2H) 7.17 (d, J=8.00 Hz, 1H) 7.20 (t, J=7.56 Hz, 1H) 7.34 (qd, J=7.00, 1.80 Hz, 1H) 7.45 (td, J=7.50, 1.59 Hz, 1H) 7.67 (br. s., 1H) 7.72 (t, J=7.56 Hz, 1H) 7.77 (dd, J=7.56, 1.22 Hz, 1H) 8.20 (dd, J=7.44, 1.46 Hz, 1H) 10.72 (br. s., 1H).

2-[1-(3-Fluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 13

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.76 (d, J=11.80 Hz, 2H) 1.84 (qd, J=11.80, 3.30 Hz, 2H) 2.12 (td, J=11.71, 2.68 Hz, 2H) 2.92 (d, J=11.34 Hz, 2H) 3.54 (s, 2H) 4.06 (tt, J=11.70, 4.00 Hz, 1H) 4.57 (s, 2H) 7.08 (td, J=8.57, 2.50 Hz, 1H) 7.15 (d, J=9.00 Hz, 1H) 7.17 (d, J=7.56 Hz, 1H) 7.38 (q, J=7.30 Hz, 1H) 7.66 (br. s., 1H) 7.72 (t, J=7.56 Hz, 1H) 7.76 (dd, J=7.56, 1.30 Hz, 1H) 8.20 (dd, J=7.50, 1.40 Hz, 1H) 10.72 (br. s., 1H).

2-{1-[(1-Methyl-1H-pyrrol-2-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 14

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.66-1.85 (m, 4H) 2.02 (br. s., 2H) 2.94 (d, J=11.10 Hz, 2H) 3.41 (s, 2H) 3.61 (s, 3H) 4.05 (quin, J=7.80 Hz, 1H) 4.55 (s, 2H) 5.88 (br. s., 2H) 6.66 (t, J=2.07 Hz, 1H) 7.66 (br. s., 1H) 7.71 (t, J=7.50 Hz, 1H) 7.75 (dd, J=7.50, 1.22 Hz, 1H) 8.19 (dd, J=7.32, 1.46 Hz, 1H) 10.72 (br. s., 1H).

3-oxo-2-{1-[4-(trifluoromethyl)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 15

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.71-1.84 (m, 2H) 1.84 (qd, J=12.10, 3.10 Hz, 2H) 2.14 (td, J=11.77, 2.80 Hz, 2H) 2.92 (d, J=11.46 Hz, 2H) 3.40-3.40 (m, 1H) 3.61 (s, 2H) 4.07 (tt, J=11.60, 4.50 Hz, 1H) 4.57 (s, 2H) 7.57 (d, J=7.93 Hz, 2H) 7.67 (br. s., 1H) 7.70 (d, J=8.05 Hz, 2H) 7.72 (t, J=7.56 Hz, 2H) 7.76 (dd, J=7.56, 1.22 Hz, 1H) 8.20 (dd, J=7.44, 1.34 Hz, 1H) 10.71 (br. s., 1H).

3-oxo-2-[1-(quinolin-2-ylmethyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 16

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.78 (d, J=11.70 Hz, 2H) 1.88 (qd, J=11.70, 3.30 Hz, 2H) 2.26 (t, J=11.34 Hz, 2H) 2.97 (d, J=11.58 Hz, 2H) 3.82 (s, 2H) 4.09 (tt, J=11.70, 4.30 Hz, 1H) 4.58 (s, 2H) 7.58 (t, J=7.44 Hz, 1H) 7.67 (d, J=8.54 Hz, 1H) 7.67 (br. s., 1H) 7.72 (t, J=7.60 Hz, 1H) 7.74 (t, J=7.68 Hz, 1H) 7.76 (dd, J=7.60, 1.30 Hz, 1H) 7.96 (d, J=8.90 Hz, 1H) 7.98 (d, J=8.90 Hz, 1H) 8.20 (dd, J=7.44, 1.34 Hz, 1H) 8.35 (d, J=8.41 Hz, 1H) 10.72 (br. s., 1H).

2-[1-(2,4-Difluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 17

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.76 (d, J=11.50 Hz, 2H) 1.81 (qd, J=11.50, 3.70 Hz, 2H) 2.14 (td, J=11.34, 2.93 Hz, 1H) 2.92 (d, J=11.58 Hz, 2H) 3.54 (s, 2H) 4.04 (tt, J=11.50, 4.50 Hz, 1H) 4.55 (s, 2H) 7.08 (td, J=8.57, 2.74 Hz, 1H) 7.20 (td, J=9.94, 2.44 Hz, 1H) 7.47 (q, J=8.00 Hz, 1H) 7.66 (br. s., 1H) 7.71 (t, J=7.50 Hz, 1H) 7.75 (dd, J=7.56, 1.30 Hz, 1H) 8.19 (dd, J=7.38, 1.40 Hz, 1H) 10.71 (br. s., 1H).

2-[1-(3,4-Dimethylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 18

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.74 (d, J=11.50 Hz, 2H) 1.80 (qd, J=11.50, 3.50 Hz, 2H) 2.05 (td, J=11.80, 3.35 Hz, 2H) 2.19 (s, 3H) 2.21 (s, 3H) 2.91 (d, J=11.22 Hz, 2H) 3.42 (s, 2H) 4.04 (tt, J=11.50, 4.50 Hz, 1H) 4.56 (s, 2H) 7.01 (d, J=7.50 Hz, 1H) 7.08 (d, J=7.50 Hz, 1H) 7.07 (br. s., 1H) 7.66 (br. s., 1H) 7.71 (t, J=7.50 Hz, 1H) 7.76 (dd, J=7.56, 1.30 Hz, 1H) 8.20 (dd, J=7.44, 1.34 Hz, 1H) 10.72 (br. s., 1H).

2-[1-(2-Methylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 19

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.70-1.88 (m, 4H) 2.09-2.21 (m, 2H) 2.35 (s, 3H) 2.87-2.97 (m, 2H) 3.47 (s, 2H) 4.02-4.14 (m, 1H) 4.57 (s, 2H) 7.12-7.28 (m, 4H) 7.67 (br. s., 1H) 7.70-7.75 (m, 1H) 7.75-7.78 (m, 1H) 8.20 (dd, J=7.32, 1.59 Hz, 1H) 10.73 (br. s., 1H).

2-[1-(2-Bromobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 20

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.75-1.92 (m, 4H) 2.18-2.29 (m, 2H) 2.94-2.99 (m, 2H) 3.60 (s, 2H) 4.05-4.16 (m, 1H) 4.58 (s, 2H) 7.19-7.25 (m, 1H) 7.40 (td, J=7.47, 1.04 Hz, 1H) 7.52 (dd, J=7.68, 1.34 Hz, 1H) 7.62 (dd, J=7.99, 0.91 Hz, 1H) 7.68 (br. s., 1H) 7.73 (t, J=7.50 Hz, 1H) 7.76-7.78 (m, 1H) 8.21 (dd, J=7.50, 1.52 Hz, 1H) 10.73 (br. s., 1H).

2-[1-(3-Bromobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 21

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.74-1.91 (m, 4H) 2.08-2.17 (m, 2H) 2.87-2.97 (m, 2H) 3.53 (s, 2H) 4.01-4.12 (m, 1H) 4.58 (s, 2H) 7.27-7.38 (m, 2H) 7.47 (d, J=7.44 Hz, 1H) 7.54 (s, 1H) 7.67 (br. s., 1H) 7.73 (t, J=7.50 Hz, 1H) 7.75-7.78 (m, 1H) 8.21 (dd, J=7.32, 1.46 Hz, 1H) 10.72 (br. s., 1H).

2-[1-(4-Bromobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 22

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.69-1.90 (m, 4H) 2.07-2.16 (m, 2H) 2.86-2.96 (m, 2H) 3.49 (s, 2H) 4.02-4.10 (m, 1H) 4.57 (s, 2H) 7.30 (d, J=8.17 Hz, 2H) 7.53 (d, J=8.29 Hz, 2H) 7.67 (br. s., 1H) 7.72 (t, J=7.50 Hz, 1H) 7.75-7.78 (m, 1H) 8.21 (dd, J=7.44, 1.34 Hz, 1H) 10.72 (br. s., 1H).

3-oxo-2-{1-[3-(trifluoromethyl)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 23

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.70-1.94 (m, 4H) 2.10-2.21 (m, 2H) 2.87-2.98 (m, 2H) 3.63 (s, 2H) 3.99-4.13 (m, 1H) 4.59 (s, 2H) 7.56-7.69 (m, 5H) 7.73 (t, J=7.50 Hz, 1H) 7.75-7.78 (m, 1H) 8.21 (dd, J=7.44, 1.46 Hz, 1H) 10.72 (br. s., 1H).

3-oxo-2-{1-[2-(trifluoromethyl)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 24

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.75-1.92 (m, 4H) 2.15-2.25 (m, 2H) 2.88-2.95 (m, 2H) 3.68 (s, 2H) 4.06-4.16 (m, 1H) 4.59 (s, 2H) 7.45-7.51 (m, 1H) 7.65-7.71 (m, 3H) 7.73 (t, J=7.50 Hz, 1H) 7.76-7.80 (m, 1H) 7.83 (d, J=7.56 Hz, 1H) 8.21 (dd, J=7.50, 1.40 Hz, 1H) 10.73 (br. s., 1H).

2-[1-(3-Methylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 25

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.71-1.91 (m, 4H) 2.03-2.13 (m, 2H) 2.32 (s, 3H) 2.87-2.99 (m, 2H) 3.47 (s, 2H) 3.99-4.13 (m, 1H) 4.58 (s, 2H) 7.05-7.16 (m, 3H) 7.22 (t, J=7.50 Hz, 1H) 7.67 (br. s., 1H) 7.72 (t, J=7.50 Hz, 1H) 7.75-7.79 (m, 1H) 8.21 (dd, J=7.50, 1.40 Hz, 1H) 10.73 (br. s., 1H).

2-{1-[(4-Methyl-1,3-thiazol-5-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 26

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.71-1.88 (m, 4H) 2.11-2.22 (m, 2H) 2.36 (s, 3H) 2.91-2.99 (m, 2H) 3.69 (s, 2H) 4.00-4.14 (m, 1H) 4.57 (s, 2H) 7.67 (br. s., 1H) 7.72 (t, J=7.44 Hz, 1H) 7.75-7.78 (m, 1H) 8.21 (dd, J=7.44, 1.46 Hz, 1H) 8.91 (s, 1H) 10.72 (br. s., 1H).

2-{1-[(1-Benzylpiperidin-4-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 27

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.00-1.20 (m, 2H) 2.16 (d, J=6.71 Hz, 2H) 2.79 (d, J=10.24 Hz, 2H) 2.94 (d, J=11.22 Hz, 2H) 3.44 (br. s., 4H) 4.04 (dt, J=10.82, 5.50 Hz, 1H) 4.56 (s, 2H) 7.20-7.36 (m, 5H) 7.67 (br. s., 1H) 7.72 (t, J=7.50 Hz, 1H) 7.75-7.78 (m, 1H) 8.21 (dd, J=7.44, 1.46 Hz, 1H) 10.73 (br. s., 1H).

2-[1-(1H-Indo)-4-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 28

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.14 (td, J=10.85, 1.83 Hz, 2H) 3.00 (d, J=11.34 Hz, 2H) 3.75 (s, 2H) 3.90-4.22 (m, 1H) 4.57 (s, 2H) 6.61 (br. s., 1H) 6.97 (d, J=6.95 Hz, 1H) 7.05 (t, J=7.44 Hz, 1H) 7.25-7.35 (m, 2H) 7.67 (br. s., 1H) 7.72 (t, J=7.50 Hz, 1H) 7.75 (d, J=1.22 Hz, 2H) 8.20 (dd, J=7.44, 1.46 Hz, 1H) 10.74 (br. s., 1H) 11.06 (br. s., 1H).

2-[1-(1H-Indo)-5-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 29

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.68-1.89 (m, 4H) 2.01-2.17 (m, 2H) 2.91-3.01 (m, 2H) 3.56 (br. s., 2H) 3.99-4.13 (m, 1H) 4.57 (s, 2H) 6.39 (br. s., 1H) 7.07 (d, J=8.17 Hz, 1H) 7.28-7.33 (m, 1H) 7.35 (d, J=8.17 Hz, 1H) 7.46 (s, 1H) 7.67 (br. s., 1H) 7.72 (t, J=7.50 Hz, 1H) 7.75-7.78 (m, 1H) 8.20 (dd, J=7.44, 1.34 Hz, 1H) 10.73 (br. s., 1H) 11.01 (br. s., 1H).

2-[1-(1H-Indo)-6-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 30

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.71-1.90 (m, 4H) 2.03-2.14 (m, 2H) 2.91-3.03 (m, 2H) 3.58 (s, 2H) 3.96-4.17 (m, 1H) 4.57 (s, 2H) 6.39 (ddd, J=2.93, 1.95, 0.85 Hz, 1H) 6.98 (dd, J=8.17, 1.34 Hz, 1H) 7.30 (dd, J=3.05, 2.56 Hz, 1H) 7.33 (s, 1H) 7.48 (d, J=8.05 Hz, 1H) 7.67 (br. s., 1H) 7.72 (t, J=7.56 Hz, 1H) 7.75-7.79 (m, 1H) 8.20 (dd, J=7.44, 1.46 Hz, 1H) 10.74 (br. s., 1H) 10.98 (br. s., 1H).

2-[1-(4-Methylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 31

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.67-1.90 (m, 4H) 2.00-2.15 (m, 2H) 2.30 (s, 3H) 2.87-2.99 (m, 2H) 3.46 (s, 2H) 4.06 (dt, J=11.71, 5.85 Hz, 1H) 4.57 (s, 2H) 7.10-7.17 (m, 2H) 7.17-7.25 (m, 2H) 7.67 (br. s., 1H) 7.70-7.75 (m, 1H) 7.76 (dd, 1H) 8.20 (dd, J=7.38, 1.40 Hz, 1H) 10.73 (br. s., 1H).

3-oxo-2-(1-{[1-(propan-2-yl)-1H-indol-3-yl]methyl}piperidin-4-yl)-2,3-dihydro-1H-isoindole-4-carboxamide cpd, 32

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.46 (d, J=6.58 Hz, 6H) 1.71-1.85 (m, 4H) 2.01-2.13 (m, 2H) 2.99-3.06 (m, 2H) 3.67 (br. s., 2H) 3.99-4.09 (m, 1H) 4.55 (s, 2H) 4.68-4.79 (m, 1H) 7.03 (t, J=7.38 Hz, 1H) 7.13 (t, J=7.44 Hz, 1H) 7.39 (s, 1H) 7.47 (d, J=8.17 Hz, 1H) 7.64-7.68 (m, 2H) 7.71 (t, J=7.50 Hz, 1H) 7.74-7.78 (m, 1H) 8.20 (dd, J=7.32, 1.34 Hz, 1H) 10.73 (br. s., 1H).

2-{1-[(1-Methyl-1H-pyrazol-4-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 33

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.65-1.88 (m, 4H) 1.92-2.07 (m, 2H) 2.87-3.06 (m, 2H) 3.37 (br. s., 2H) 3.81 (s, 3H) 3.94-4.12 (m, 1H) 4.55 (s, 2H) 7.31 (s, 1H) 7.56-7.59 (m, 1H) 7.67 (br. s., 1H) 7.72 (t, J=7.56 Hz, 1H) 7.75-7.78 (m, 1H) 8.20 (dd, J=7.50, 1.40 Hz, 1H) 10.72 (br. s., 1H).

2-{1-[(1,5-Dimethyl-1H-pyrazol-4-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 34

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.67-1.87 (m, 4H) 1.93-2.06 (m, 1H) 2.21 (s, 3H) 2.85-3.01 (m, 2H) 3.71 (s, 3H) 3.91-4.15 (m, 1H) 4.55 (s, 2H) 7.22 (s, 1H) 7.67 (br. s., 1H) 7.72 (t, J=7.50 Hz, 1H) 7.75-7.78 (m, 1H) 8.20 (dd, J=7.44, 1.46 Hz, 1H) 10.73 (br. s., 1H).

2-[1-(3-Methoxybenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 35

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.71-1.89 (m, 4H) 2.04-2.14 (m, 2H) 2.89-2.98 (m, 2H) 3.49 (s, 2H) 3.76 (s, 3H) 4.01-4.11 (m, 1H) 4.58 (s, 2H) 6.81-6.85 (m, 1H) 6.92 (s, 1H) 6.90 (d, J=1.59 Hz, 1H) 7.25 (t, J=7.87 Hz, 1H) 7.67 (br. s., 1H) 7.72 (t, J=7.51 Hz, 1H) 7.75-7.79 (m, 1H) 8.21 (dd, J=7.45, 1.46 Hz, 1H) 10.73 (br. s., 1H).

2-{1-[(3-Methylthiophen-2-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 36

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.73-1.89 (m, 4H) 2.08-2.16 (m, 2H) 2.17-2.18 (m, 3H) 2.96-3.03 (m, 2H) 3.62 (s, 2H) 4.07 (dt, J=10.68, 5.40 Hz, 1H) 4.58 (s, 2H) 6.84 (d, J=5.13 Hz, 1H) 7.32 (d, J=5.13 Hz, 1H) 7.67 (br. s., 1H) 7.70-7.75 (m, 1H) 7.75-7.78 (m, 1H) 8.21 (dd, J=7.38, 1.40 Hz, 1H) 10.73 (br. s., 1H).

3-oxo-2-[1-(4-propoxybenzyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 37

¹H NMR (400 MHz, DMSO-d₆) δ ppm 0.98 (t, J=7.38 Hz, 3H) 1.68-1.85 (m, 6H) 2.00-2.10 (m, 2H) 2.87-2.96 (m, 2H) 3.43 (s, 2H) 3.91 (t, J=6.53 Hz, 2H) 3.99-4.10 (m, 1H) 4.57 (s, 2H) 6.89 (d, J=8.54 Hz, 2H) 7.22 (d, J=8.67 Hz, 2H) 7.67 (br. s., 1H) 7.69-7.75 (m, 1H) 7.75-7.78 (m, 1H) 8.20 (dd, J=7.45, 1.34 Hz, 1H) 10.73 (br. s., 1H).

3-oxo-2-{1-[4-(propan-2-yl)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 38

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.21 (d, J=6.96 Hz, 6H) 1.67-1.90 (m, 4H) 1.99-2.15 (m, 2H) 2.83-2.89 (m, 1H) 2.88-2.96 (m, 2H) 3.47 (s, 2H) 4.00-4.12 (m, 1H) 4.57 (s, 2H) 7.16-7.29 (m, 4H) 7.67 (br. s., 1H) 7.72 (t, J=7.51 Hz, 1H) 7.75-7.79 (m, 1H) 8.20 (dd, J=7.51, 1.40 Hz, 1H) 10.73 (br. s., 1H).

2-[1-(4-Methoxybenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 39

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.67-1.87 (m, 4H) 2.05 (td, J=11.32, 2.38 Hz, 2H) 2.91 (d, J=11.47 Hz, 1H) 3.43 (s, 2H) 3.74 (s, 3H) 3.96-4.12 (m, 1H) 4.56 (s, 2H) 6.89 (d, J=8.42 Hz, 2H) 7.23 (d, J=8.30 Hz, 2H) 7.66 (br. s., 1H) 7.71 (t, J=7.51 Hz, 1H) 7.76 (dd, J=7.51, 1.20 Hz, 1H) 8.19 (dd, J=7.45, 1.46 Hz, 1H) 10.72 (br. s., 1H).

2-[1-(3-Ethoxybenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 40

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.33 (t, J=7.02 Hz, 3H) 1.75 (dd, J=11.84, 4.00 Hz, 2H) 1.82 (qd, J=11.84, 3.66 Hz, 2H) 2.08 (td, J=11.57, 2.62 Hz, 2H) 2.92 (d, J=11.72 Hz, 2H) 3.47 (s, 2H) 4.01 (q, J=6.96 Hz, 2H) 4.05 (tt, J=11.84, 4.50 Hz, 2H) 4.57 (s, 2H) 6.80 (dd, J=7.32, 1.83 Hz, 1H) 6.87 (br. s., 1H) 6.88 (d, J=7.00 Hz, 1H) 7.22 (t, J=8.06 Hz, 1H) 7.66 (br. s., 1H) 7.71 (t, J=7.51 Hz, 1H) 7.76 (dd, J=7.51, 1.30 Hz, 1H) 8.20 (dd, J=7.45, 1.34 Hz, 1H) 10.72 (br. s., 1H).

3-oxo-2-{1-[2-(propan-2-yloxy)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 41

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.28 (d, J=6.10 Hz, 6H) 1.75 (dd, J=11.78, 4.00 Hz, 2H) 1.82 (qd, J=11.78, 3.48 Hz, 2H) 2.13 (td, J=11.50, 2.38 Hz, 2H) 2.95 (d, J=11.60 Hz, 2H) 3.49 (s, 2H) 4.05 (tt, J=11.47, 4.70 Hz, 1H) 4.60 (spt, J=6.00 Hz, 1H) 4.56 (s, 2H) 6.90 (td, J=7.38, 0.98 Hz, 1H) 6.98 (d, J=7.93 Hz, 1H) 7.19 (ddd, J=8.39, 7.05, 1.77 Hz, 1H) 7.34 (dd, J=7.51, 1.65 Hz, 1H) 7.66 (br. s., 1H) 7.71 (t, J=7.57 Hz, 1H) 7.76 (dd, J=7.57, 1.30 Hz, 1H) 8.20 (dd, J=7.57, 1.34 Hz, 1H) 10.73 (br. s., 1H).

2-[1-(3-Chlorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 42

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.68-1.87 (m, 4H) 2.09 (td, J=11.50, 2.38 Hz, 2H) 2.89 (d, J=11.60 Hz, 2H) 3.50 (s, 2H) 3.91-4.16 (m, 1H) 4.55 (s, 2H) 7.24-7.31 (m, 2H) 7.30-7.35 (m, 1H) 7.35-7.37 (m, 1H) 7.64 (br. s., 1H) 7.69 (t, J=7.51 Hz, 1H) 7.72-7.76 (m, 1H) 8.17 (dd, J=7.45, 1.46 Hz, 1H) 10.69 (br. s., 1H)

2-[1-(4-Ethylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 43

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.18 (t, J=7.57 Hz, 3H) 1.65-1.87 (m, 4H) 2.00-2.11 (m, 2H) 2.59 (q, J=7.65 Hz, 2H) 2.85-3.00 (m, 2H) 3.46 (s, 2H) 4.05 (q, J=10.99 Hz, 0H) 4.56 (s, 2H) 7.14-7.18 (m, 2H) 7.19-7.26 (m, 2H) 7.66 (br. s., 1H) 7.71 (t, J=7.51 Hz, 1H) 7.74-7.78 (m, 1H) 8.19 (dd, J=7.45, 1.34 Hz, 1H) 10.72 (br. s., 1H).

3-oxo-2-{1-[4-(propan-2-yloxy)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 44

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.25 (d, J=5.98 Hz, 5H) 1.63-1.88 (m, 4H) 1.99-2.13 (m, 2H) 2.85-2.98 (m, 2H) 3.42 (s, 2H) 3.94-4.16 (m, 1H) 4.46-4.67 (m, 3H) 6.78-6.93 (m, 2H) 7.20 (d, J=8.67 Hz, 2H) 7.66 (br. s., 1H) 7.71 (t, J=7.51 Hz, 1H) 7.74-7.77 (m, 1H) 8.19 (dd, J=7.45, 1.34 Hz, 1H) 10.72 (br. s., 1H).

2-{1-[(5-Methylthiophen-2-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 45

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.71-1.86 (m, 4H) 2.09 (td, J=10.71, 3.97 Hz, 2H) 2.40 (d, J=0.61 Hz, 2H) 2.91-3.03 (m, 2H) 3.62 (s, 2H) 4.04 (m, J=10.45, 10.45, 5.61, 5.34 Hz, 1H) 4.56 (s, 2H) 6.63 (dd, J=3.30, 1.10 Hz, 1H) 6.74 (d, J=3.30 Hz, 1H) 7.66 (br. s., 1H) 7.71 (t, J=7.51 Hz, 1H) 7.74-7.79 (m, 1H) 8.20 (dd, J=7.51, 1.40 Hz, 1H) 10.72 (br. s., 1H).

2-{[1-(4-Methylbenzyl)piperidin-4-yl]methyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 47

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.23 (q, J=11.06 Hz, 2H) 1.58 (d, J=12.44 Hz, 2H) 1.76 (br. s., 1H) 1.89 (t, J=11.95 Hz, 2H) 2.27 (s, 3H) 2.77 (d, J=9.51 Hz, 2H) 3.39 (br. s., 2H) 3.46 (d, J=7.19 Hz, 2H) 4.57 (s, 2H) 7.11 (d, J=7.00 Hz, 2H) 7.16 (d, J=7.00 Hz, 2H) 7.66 (br. s., 1H) 7.71 (t, J=7.50 Hz, 1H) 7.75 (dd, J=7.45, 1.50 Hz, 1

H) 8.20 (dd, J=7.38, 1.52 Hz, 1H) 10.72 (br. s., 1H).

2-(3-Isobutylamino-propyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid amide, cpd 107

ESI(+) MS: m/z 290 (MH⁺).

2-{3-[Bis(2-methylpropyl)amino]propyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 48

Cpd 48 was obtained operating in an analogous way as in Conversion 3, Example 1, employing 2-(3-isobutylamino-propyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid amide as starting material.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 0.86 (d, J=6.47 Hz, 12H) 1.66 (spt, J=6.60 Hz, 2H) 1.75 (quin, J=6.70 Hz, 2H) 2.06 (d, J=6.84 Hz, 4H) 2.37 (t, J=6.59 Hz, 2H) 3.60 (t, J=7.45 Hz, 2H) 4.57 (s, 2H) 7.66 (br. s., 1H) 7.71 (t, J=7.57 Hz, 1H) 7.77 (dd, J=7.50, 1.10 Hz, 1H) 8.20 (dd, J=7.57, 1.22 Hz, 1H) 10.76 (br. s., 1H).

2-{[1-(3-Methylbenzyl)piperidin-4-yl]methyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 49

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.23 (qd, J=11.96, 3.78 Hz, 2H) 1.58 (dd, J=13.18, 3.30 Hz, 1H) 1.76 (m, J=11.18, 11.18, 7.47, 7.47, 3.75, 3.75 Hz, 1H) 1.90 (td, J=11.57, 2.01 Hz, 2H) 2.28 (s, 3H) 2.77 (dt, J=11.47, 3.36 Hz, 2H) 3.39 (s, 2H) 3.46 (d, J=7.32 Hz, 2H) 4.57 (s, 2H) 7.03 (d, J=7.69 Hz, 1H) 7.08 (d, J=7.81 Hz, 1H) 7.04 (br. s., 1H) 7.18 (t, J=7.45 Hz, 1H) 7.66 (br. s., 1H) 7.71 (t, J=7.40 Hz, 1H) 7.75 (dd, J=7.50, 1.50 Hz, 1H) 8.20 (dd, J=7.38, 1.53 Hz, 1H) 10.72 (br. s., 1H).

2-(3-Cyclopentylamino-propyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid amide, cpd 108

ESI(+) MS: m/z 302 (MH⁺).

2-{3-[Cyclopentyl(furan-2-ylmethyl)amino]propyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 50

Cpd 50 was obtained operating in an analogous way as in Conversion 3, employing 2-(3-cyclopentylamino-propyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxylic acid amide as starting material.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.55 (br. s., 2H) 1.71 (br. s., 4H) 2.07 (br. s., 4H) 3.02 (br. s., 2H) 3.53 (br. s., 1H) 3.63 (t, J=6.47 Hz, 2H) 4.32-4.55 (m, 2H) 4.59 (s, 2H) 6.42 (dd, J=3.05, 1.95 Hz, 1H) 6.69 (br. s., 1H) 7.61 (d, J=1.04 Hz, 1H) 7.70 (br. s., 1H) 7.76 (t, J=7.57 Hz, 1H) 7.81 (dd, J=7.50, 1.00 Hz, 1H) 8.22 (dd, J=7.63, 1.04 Hz, 1H) 9.71 (br. s., 1H) 10.56 (d, J=0.49 Hz, 1H).

2-{[1-(4-Fluorobenzyl)piperidin-4-yl]methyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 51

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.23 (q, J=11.38 Hz, 2H) 1.59 (d, J=12.19 Hz, 2H) 1.77 (br. s., 1H) 1.91 (t, J=11.40 Hz, 2H) 2.77 (d, J=9.27 Hz, 2H) 3.43 (br. s., 1H) 3.46 (d, J=7.32 Hz, 2H) 4.57 (s, 2H) 7.12 (t, J=8.72 Hz, 2H) 7.31 (t, J=6.89 Hz, 2H) 7.66 (br. s., 1H) 7.71 (t, J=7.40 Hz, 1H) 7.75 (dd, J=7.40, 1.50 Hz, 1H) 8.20 (dd, J=7.32, 1.59 Hz, 1H) 10.71 (br. s., 1H).

2-[1-(2-Methoxyethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 106

¹H NMR (400 MHz, DMSO-d₆) δ ppm 10.73 (br. s., 1H), 8.20 (dd, J=1.28, 7.51 Hz, 1H), 7.76 (dd, J=1.20, 7.57 Hz, 1H), 7.71 (t, J=7.57 Hz, 1H), 7.66 (br. s., 1H), 4.55 (s, 2H), 4.03 (tt, J=5.00, 11.14 Hz, 1H), 3.44 (t, J=5.80 Hz, 2H), 3.24 (s, 3H), 2.99 (d, J=11.72 Hz, 2H), 2.10 (td, J=2.93, 11.72 Hz, 1H), 1.80 (qd, J=3.66, 12.08 Hz, 2H), 1.68-1.80 (m, 2H)

Preparation of 4,4-dichlorocyclohexanone

To a slurry of powdered molecular sieves (1 g) in dry methanol (10 mL), hydrazine hydrate (2.92 mL, 60 mmol) was added, and the suspension was stirred at room temperature for 15 min. A solution of 1,4-dioxaspiro[4.5]decan-8-one (0.47 g, 3 mmol) in dry methanol (6 mL) was then added to the slurry and the reaction mixture was stirred for 2 hours. The suspension was then filtered on a pad of Celite, which was washed with methanol. Volatiles were removed under high vacuum by keeping the bath temperature at 60° C. In the meantime, to a stirred suspension of copper(II) chloride (2.82 g, 21 mmol) in dry methanol (10 mL), kept under nitrogen, triethylamine (1.5 mL, 10.8 mmol) was slowly added at room temperature, the resulting solution was stirred for 30 min then cooled to 0° C. and left under stirring for an additional 2 hours. To this solution, the previously prepared crude hydrazone, dissolved in dry methanol (8 mL), was then added dropwise during 30 min, while keeping the temperature at 0° C. The reaction mixture was then stirred at room temperature for 1 hour, quenched with saturated aqueous ammonium chloride, diluted with water and treated with aqueous 2N hydrochloric acid until complete dissolution of copper salts. The aqueous phase was extracted twice with diethyl ether, the combined organic phases were washed with water, brine, dried over sodium sulfate and then evaporated to dryness. The crude was purified by column chromatography (n-hexane/ethyl acetate 95:5) affording the desired 8,8-dichloro-1,4-dioxaspiro[4.5]decane as a white solid (0.31 g, 50% yield).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.69-1.81 (m, 4H), 2.37-2.45 (m, 4H), 3.89 (s, 4H)

To a solution of 8,8-dichloro-1,4-dioxaspiro[4.5]decane (0.27 g, 1.28 mmol) in acetone (3.5 mL), aqueous 2N hydrochloric acid (5 mL) was added and the reaction mixture was stirred at room temperature overnight, diluted with water and extracted twice with diethyl ether. The combined organic phases were washed with water, brine, dried over sodium sulfate and evaporated to dryness. The resulting crude 4,4-dichlorocyclohexanone, obtained as a white solid, was used in the next steps without any further purification (0.17 g, 78% yield).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.44-2.49 (m, 4H), 2.70-2.77 (m, 4H)

Preparation of 1-(4,4-difluorocyclohexyl)-piperidin-4-ylamine

To a stirred solution of piperidin-4-yl-carbamic acid tert-butyl ester (2.00 g, 10 mmol) and 4,4-difluorocyclohexanone (1.61 g, 12 mmol) in N,N-dimethylformamide (50 mL), kept at room temperature, acetic acid (3 mL, 50 mmol) and tetramethylammonium triacetoxyborohydride (5.24 g, 20 mmol) were subsequently added. The reaction mixture was allowed to stir overnight then diluted with water (150 mL), extracted with diethyl ether and the organic layer was discarded. The aqueous phase was made basic with ammonia and extracted with ethyl acetate (3×100 mL). The combined organic phases were dried over sodium sulfate, evaporated to dryness and the residue was purified by column chromatography, using dichloromethane/ethanol/concentrated aqueous ammonia: 97.5/2.5/0.25 as the mobile phase. Tert-butyl [1-(4,4-difluorocyclohexyl)-piperidin-4-yl]-carbamate was obtained in fairly good yield as a white solid (2.5 g, 78%).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 6.71 (d, J=9.64 Hz, 1H), 3.07-3.21 (m, 1H), 2.71-2.83 (m, 2H), 2.35-2.46 (m, 1H), 2.08-2.17 (m, 2H), 1.93-2.06 (m, 2H), 1.77-1.90 (m, 1H), 1.59-1.76 (m, 5H), 1.42-1.57 (m, 2H), 1.37 (s, 9H), 1.26-1.34 (m, 2H)

Operating in an analogous way, but replacing 4,4-difluorocyclohexanone with 4,4-dichlorocyclohexanone the following compound was obtained:

Tert-butyl [1-(4,4-dichlorocyclohexyl)piperidin-4-yl]carbamate

¹H NMR (400 MHz, DMSO-d₆) δ ppm 6.61-6.80 (m, 1H), 3.16 (br. s., 1H), 2.70-2.82 (m, 2H), 2.35-2.48 (m, 3H), 2.21-2.31 (m, 2H), 2.06-2.19 (m, 2H), 1.37 (s, 9H).

To a stirred solution of [1-(4,4-difluorocyclohexyl)-piperidin-4-yl]-carbamic acid tert-butyl ester (2.5 g, 7.86 mmol) in dioxane (5 mL), kept at room temperature, 4N acid chloride in dioxane (20 mL, 78.6 mmol) were added. The reaction mixture was stirred overnight at room temperature, diluted with water, made basic with concentrated aqueous ammonia ed extracted with dichloromethane (5×100 mL). The combined organic phases were washed with brine, dried over sodium sulfate, and evaporated to dryness in vacuo. The title compound was obtained in quantitative yield (1.7 g, 7.8 mmol) as a tick oil turning to a white, deliquescent solid on standing in the fridge.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.69-2.77 (m, 2H), 2.35-2.44 (m, J=3.42 Hz, 1H), 2.06-2.16 (m, 2H), 1.92-2.05 (m, J=14.16 Hz, 2H), 1.75-1.89 (m, 2H), 1.61-1.75 (m, 5H), 1.41-1.57 (m, J=12.33 Hz, 2H), 1.09-1.24 (m, 2H)

Operating in an analogous way, but employing suitable substituted starting material the following compound was obtained:

1-(4,4-Dichlorocyclohexyl)piperidin-4-amine

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.69-2.79 (m, 2H), 2.42-2.47 (m, 2H), 2.34-2.42 (m, 1H), 2.20-2.30 (m, 2H), 2.06-2.16 (m, 2H), 1.56-1.78 (m, 7H), 1.11-1.23 (m, 2H).

Example 3 Step i+Step e Methyl 4-chloro-2-iodo-6-methylbenzoate

4-Chloro-2-methylbenzoic acid (1.7 g, 10 mmol), palladium(II) acetate (112 mg, 0.5 mmol), iodobenzene diacetate (6.44 g, 20 mmol) and elemental iodine (5.08 g, 20 mmol) were dissolved in N,N-dimethylformamide (50 mL) and stirred overnight at 100° C. The reaction mixture was cooled to room temperature, diluted with methyl-tert-butylether and 2M hydrochloric acid and washed with 10% aqueous solution of sodium metabisulphite. Organic phase was extracted with 2M sodium hydroxide and the resulting basic aqueous phase was acidified with concentrated aqueoushydrochloric acid and re-extracted with methyl-tert-butylether. The solvent was removed under reduced pressure affording 4-chloro-2-iodo-6-methylbenzoic acid (2.8 g, 94% yield) without further purification. So obtained iodinated benzoic acid (2.8 g, 9.4 mmol) was dissolved in N,N-dimethylformamide (25 mL) and methyliodide (1.25 mL, 20 mmol) and potassium carbonate (2.8 g, 20 mmol) were added. The reaction mixture was stirred overnight at room temperature, diluted with methyl-tert-butylether and washed with water, 1M sodium hydroxide, water and brine. Solvent was removed under reduced pressure and the crude was purified by flash chromatography (n-hexane/diethyl ether 100:2) to give title compound (2.2 g, 75% yield).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.25 (s, 3H) 3.87 (s, 3H) 7.46 (dd, J=2.01, 0.67 Hz, 1H) 7.82 (dd, J=1.95, 0.49 Hz, 1H).

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained:

Methyl 4-fluoro-2-iodo-6-methylbenzoate

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.27 (s, 3H) 3.86 (s, 3H) 7.21-7.27 (m, 1H) 7.63 (m, J=8.18, 2.44, 0.40, 0.40, 0.40 Hz, 1H).

Methyl 3-fluoro-6-iodo-2-methylbenzoate

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.16 (d, J=2.32 Hz, 3H) 3.89-3.90 (m, 3H) 7.05-7.14 (m, 1H) 7.75 (ddd, J=8.67, 5.00, 0.61 Hz, 1H)

Methyl 5-fluoro-6-iodo-2-methylbenzoate

¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.30-7.37 (m, 1H), 7.21-7.28 (m, 1H), 3.89 (s, 3H), 2.24 (s, 3H)

Step f 2-[1-(4,4-Difluorocyclohexyl)piperidin-4-yl]-5-chloro-7-iodo-2,3-dihydro-1H-isoindol-1-one

To a solution of methyl 4-chloro-2-iodo-6-methylbenzoate (175 mg, 0.56 mmol) in methyl pivalate (1 mL), N-bromosuccinimide (120 mg, 0.67 mmol) and benzoylperoxide (14 mg, 0.06 mmol) were added. The reaction mixture was stirred at 85° C. under nitrogen atmosphere for 3 hours. Additional N-bromosuccinimide (60 mg) and benzoylperoxide (7 mg) were added and stirring continued for 1 hour. Crude was filtered on Gooch and washed with toluene. Volatiles were evaporated and the residue was dissolved in acetonitrile (2 mL). Triethylamine (0.28 mL, 2 mmol) and 1-(4,4-difluorocyclohexyl)-piperidin-4-ylamine (110 mg, 0.5 mmol) were added and the reaction mixture was stirred at 90° C. for 4 hours. Crude was diluted with dichloromethane and washed with 15% ammonium hydroxide. Organic phase was dried over sodium sulfate, filtered and evaporated. Column chromatography (dichloromethane/ethanol:97/3) afforded title compound (116 mg, 45% yield).

ESI(+) MS: m/z 495 (MH⁺).

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained:

2-[1-(4,4-Difluorocyclohexyl)piperidin-4-yl]-5-fluoro-7-iodo-2,3-dihydro-1H-isoindol-1-one

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.19-2.33 (m, 2H) 2.93 (d, J=10.62 Hz, 2H) 3.87-4.01 (m, 1H) 4.37 (s, 2H) 7.51 (dd, J=8.24, 2.26 Hz, 1H) 7.80 (dd, J=8.91, 2.20 Hz, 1H).

2-[1-(4,4-Difluorocyclohexyl)piperidin-4-yl]-4-fluoro-7-iodo-2,3-dihydro-1H-isoindol-1-one

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.27 (m, J=2.81 Hz, 2H) 2.94 (m, J=11.72 Hz, 2H) 3.88-4.04 (m, 1H) 4.47 (s, 2H) 7.24 (t, J=8.61 Hz, 1H) 7.92 (dd, J=8.54, 4.52 Hz, 1H).

Step q 6-Chloro-2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carbonitrile

2-[1-(4,4-Difluorocyclohexyl)piperidin-4-yl]-5-chloro-7-iodo-2,3-dihydro-1H-isoindol-1-one (80 mg, 0.16 mmol) and copper(I) cyanide (22 mg, 0.24 mmol) were dissolved in N,N-dimethylformamide (1 mL) and the resulted solution was refluxed under nitrogen atmosphere for 3 hours. The solvent was removed under reduced pressure and the residue was diluted with dichloromethane and washed with 15% ammonium hydroxide. Organic phase was dried over sodium sulfate, filtered and evaporated. Column chromatography (dichloromethane/ethanol:95/5) afforded title compound (46 mg, 72% yield).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.46-2.10 (m, 12H) 2.23-2.33 (m, 2H) 2.94 (d, J=11.35 Hz, 2H) 3.90-4.04 (m, 1H) 4.51-4.53 (m, 2H) 8.06 (d, J=1.83 Hz, 1H) 8.15 (d, J=1.83 Hz, 1H).

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained:

6-Fluoro-2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carbonitrile

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.22-2.36 (m, 2H) 2.94 (d, J=11.47 Hz, 2H) 3.89-4.01 (m, 1H) 4.51-4.54 (m, 2H) 7.81-7.88 (m, 1H) 7.96-8.01 (m, 1H)

7-Fluoro-2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carbonitrile

ESI(+) MS: m/z 378 (MH⁺).

Step h 2-[1-(4,4-Difluorocyclohexyl)-piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 99

To a stirred solution of [2-[1-(4,4-difluorocyclohexyl)-piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carbonitrile (1.44 g, 3.82 mmol) in acetic acid (11 mL), concentrated sulfuric acid (5.8 mL) was added dropwise during 30 min. The reaction was then warmed at 80° C. for 9 hours, cooled at room temperature and poured into cold water (20 mL). The aqueous phase was then made basic by adding concentrated aqueous ammonia and extracted with dichloromethane (3×10 mL). The combined organic phases were washed with 2N aqueous sodium hydroxide (2×12 mL) and brine, dried over sodium sulfate, and evaporated to dryness in vacuo. The title compound was obtained as a white solid (1 g, 67%) after purification through column chromatography, using dichloromethane/ethanol:95/5 as the mobile phase.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 10.77 (br. s., 1H), 7.89 (dd, J=2.56, 10.86 Hz, 1H), 7.85 (br. s., 1H), 7.66 (dd, J=2.62, 7.75 Hz, 1H), 4.56 (s, 2H), 3.88-4.09 (m, 1H), 2.86-3.01 (m, 2H), 2.18-2.34 (m, 2H).

The following compound was isolated as side-product:

6-Fluoro-3-oxo-2-[1-(4-oxocyclohexyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 103

¹H NMR (400 MHz, DMSO-d₆) ppm 10.77 (br. s., 1H), 7.89 (d, J=8.18 Hz, 1H), 7.85 (br. s., 1H), 7.64-7.70 (m, 1H), 7.67 (dd, J=2.50, 7.63 Hz, 1H), 4.57 (s, 2H), 4.02 (br. s., 2H), 2.79 (br. s., 2H).

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained

2-[1-(4,4-Difluorocyclohexyl)-piperidin-4-yl]-6-chloro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 100

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.54 (m, J=9.15 Hz, 2H) 1.75 (m, J=7.08 Hz, 6H) 2.04 (m, J=18.55 Hz, 2H) 2.28 (m, J=2.93 Hz, 2H) 2.94 (m, J=11.23 Hz, 2H) 4.00 (m, J=4.64 Hz, 1H) 4.56 (s, 2H) 7.86 (br. s., 1H) 7.89 (d, J=2.07 Hz, 1H) 8.12 (d, J=2.08 Hz, 1H) 10.68 (br. s., 1H)₂-[1-(4,4-Difluorocyclohexyl)-piperidin-4-yl]-7-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 101

¹H NMR (400 MHz, DMSO-d₆) δ ppm 2.23-2.33 (m, 2H) 2.89-3.00 (m, 2H) 4.01 (br. s., 1H) 4.63 (s, 2H) 7.57 (t, J=8.48 Hz, 1H) 7.71 (br. s., 1H) 8.26 (dd, J=8.73, 5.19 Hz, 1H) 10.55 (br. s., 1H).

2-[1-(4,4-Difluorocyclohexyl)-piperidin-4-yl]-5-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 102

¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.86 (s, 1H), 7.62 (s, 1H), 7.59 (dd, J=4.58, 8.36 Hz, 1H), 7.44 (dd, J=8.36, 9.70 Hz, 1H), 4.42 (s, 2H), 3.88-3.99 (m, 1H), 2.93 (d, J=11.72 Hz, 2H), 2.27 (br. s., 2H).

The following compound was isolated as side-product:

5-Fluoro-3-oxo-2-[1-(4-oxocyclohexyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 104

ESI(+) MS: m/z 374 (MH⁺).

Example 4 Step re Methyl 2-cyano-3-fluoro-6-methylbenzoate

Methyl 3-fluoro-2-iodo-6-methylbenzoate (440 mg, 1.49 mmol) and copper(I) cyanide (200 mg, 2.24 mmol) were dissolved in N,N-dimethylformamide (5.5 mL) and the resulted solution was refluxed under nitrogen atmosphere for 3 hours. The solvent was removed under reduced pressure and the residue was diluted with dichloromethane and washed with 15% ammonium hydroxide. Organic phase was dried over sodium sulfate, filtered and evaporated. Column chromatography (n-hexane/ethyl acetate: 7/3) afforded title compound (210 mg, 73% yield).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.76 (dd, J=5.56, 8.76 Hz, 1H), 7.61-7.67 (m, 1H), 3.94 (s, 3H), 2.38 (s, 3H)

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained:

Methyl 2-cyano-4-fluoro-6-methylbenzoate

¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.79-7.91 (m, 1H), 7.65 (ddd, J=0.67, 2.62, 9.64 Hz, 1H), 3.93 (s, 3H), 2.42 (s, 3H).

Step f″ 2-[1-(4,4-Difluorocyclohexyl)piperidin-4-yl]-5-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carbonitrile

To a solution of methyl 2-cyano-3-fluoro-6-methylbenzoate (208 mg, 1.07 mmol) in methyl pivalate (2 mL), N-bromosuccinimide (310 mg, 1.74 mmol) and benzoylperoxide (20 mg, 0.097 mmol) were added. The reaction mixture was stirred at 85° C. under nitrogen atmosphere for 3 hours. Crude was filtered on Gooch and washed with toluene. Volatiles were evaporated and the residue was dissolved in acetonitrile (3 mL). Triethylamine (0.41 mL, 2.9 mmol) and 1-(4,4-difluorocyclohexyl)-piperidin-4-ylamine (280 mg, 0.97 mmol) were added and the reaction mixture was stirred at 90° C. for 3 hours. Crude was diluted with dichloromethane and washed with 15% ammonium hydroxide Organic phase was dried over sodium sulfate, filtered and evaporated. Column chromatography (dichloromethane/ethanol:95/5) afforded title compound (222 mg, 60% yield).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.98 (dd, J=4.64, 8.54 Hz, 1H), 7.74 (dd, J=8.54, 9.76 Hz, 1H), 4.51 (s, 2H), 3.90-4.04 (m, 1H), 2.91-2.98 (m, 2H), 2.22-2.33 (m, 2H)

Operating in an analogous way, but employing suitably substituted starting material the following compounds were obtained:

2-[1-(4,4-Difluorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carbonitrile

¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.96-8.01 (m, 1H), 7.81-7.88 (m, 1H), 4.51-4.54 (m, 2H), 3.89-4.01 (m, 1H), 2.94 (d, J=11.47 Hz, 2H), 2.22-2.36 (m, 2H).

2-[1-(4,4-Dichlorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carbonitrile

¹H NMR (400 MHz, DMSO-d₆) δ ppm 7.98 (dd, J=2.26, 9.22 Hz, 1H), 7.86 (dd, J=2.14, 8.24 Hz, 1H), 4.52 (s, 2H), 3.92-4.01 (m, 1H), 2.94 (d, J=9.28 Hz, 2H), 2.48 (br. s., 2H), 2.29 (br. s., 4H), 1.61-1.82 (m, 8H).

Example 5 2-[1-(4,4-Difluorocyclohexyl)-piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 99

To a solution of 2-[1-(4,4-difluorocyclohexyl)-piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carbonitrile (2.81 g; 7.44 mmol) in toluene (28 mL) acetaldoxime (4.4 g; 74.4 mmol) and indium(III) chloride (82 mg; 0.37 mmol) were added at room temperature. The resulting solution was heated at reflux for 1 hour, then concentrated under reduced pressure. The residue was taken-up with water, isopropanol and dichloromethane. The organic layer was separated and finally concentrated under reduced pressure. The resulting crude was crystallized from ethanol delivering, after drying, 1.82 g of 2-[1-(4,4-difluorocyclohexyl)-piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, as a white solid (62% yield).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 10.77 (br. s., 1H), 7.89 (dd, J=2.56, 10.86 Hz, 1H), 7.85 (br. s., 1H), 7.66 (dd, J=2.62, 7.75 Hz, 1H), 4.56 (s, 2H), 3.88-4.09 (m, 1H), 2.86-3.01 (m, 2H), 2.18-2.34 (m, 2H).

Operating in an analogous way, but employing suitably substituted starting material the following compound was obtained:

2-[1-(4,4-Dichlorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide, cpd 105

¹H NMR (400 MHz, DMSO-d₆) δ ppm 10.77 (br. s., 1H), 7.89 (dd, J=2.50, 10.80 Hz, 1H), 7.86 (br. s., 1H), 7.67 (d, J=6.84 Hz, 1H), 4.54-4.57 (m, 2H), 4.00 (br. s., 1H), 2.85-3.02 (m, 1H), 2.18-2.36 (m, 3H), 1.97-2.16 (m, 1H), 1.55-1.84 (m, 6H).

Probe Experimental Preparation Step i₀ 2-Methylamino-N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-acetamide

To a stirred suspension of 2-chloro-N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-acetamide (XVIII, Lg=Cl, 150 mg, 0.52 mmol) in N,N-dimethylformamide (1.4 mL), a 33% solution of methylamine in ethanol was added (9 mL, 72 mM). The reaction mixture was stirred at room temperature for 3 hours. The ethanol was then evaporated under reduced pressure and the mixture was diluted with diethyl ether and filtered. A light-yellow solid was then collected, washed with diethyl ether then with cold water and dried. The title compound was obtained in moderate yield (100 mg, 68%).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 11.68 (s, 1H), 10.33 (br. s., 1H), 8.61 (d, J=2.1 Hz, 1H), 8.34 (dd, J=7.9, 1.1 Hz, 1H), 8.26 (d, J=8.2 Hz, 1H), 7.89 (ddd, J=8.2, 7.1, 1.4 Hz, 1H), 7.70 (dd, J=8.7, 2.2 Hz, 1H), 7.67 (ddd, J=7.9, 7.2, 0.7 Hz, 1H), 7.35 (d, J=8.8 Hz, 1H), 3.68 (s, 2H), 2.54 (s, 3H).

Step i_(a) (3-{[(6-oxo-5,6-dihydro-phenanthridin-2-ylcarbamoyl)-methyl]-amino}-propyl)-carbamic acid tert-butyl ester

To a stirred suspension of 2-chloro-N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-acetamide (XVIII, Lg=Cl) (50 mg, 0.17 mmol) in N,N-dimethylformamide (2 mL), (3-amino-propyl)-carbamic acid tert-butyl ester (0.09 mL, 0.51 mmol) and triethylamine (0.036 mL, 0.26 mmol) were added. The reaction mixture was stirred at room temperature overnight, evaporated to dryness and then purified through by preparative HPLC on a Waters X Terra RP 18 (19×250 mm, 5 μm) column. Mobile phase A was 0.05% ammonium hydroxide/acetonitrile:95/5 and mobile phase B was acetonitrile/water:95/5. Gradient from 10 to 75% B in 15 min. Fractions containing the desired compound were dried, affording 32 mg (44% yield) of the title compound.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 11.65 (s, 1H), 10.09 (br. s., 1H), 8.63 (d, J=2.0 Hz, 1H), 8.33 (dd, J=7.9, 1.2 Hz, 1H), 8.28 (d, J=8.2 Hz, 1H), 8.12-8.12 (m, 1H), 7.88 (ddd, J=8.2, 7.1, 1.4 Hz, 1H), 7.72 (dd, J=8.8, 2.0 Hz, 1H), 7.66 (ddd, J=8.0, 7.1, 0.7 Hz, 1H), 7.33 (d, J=8.8 Hz, 1H), 6.83 (t, J=5.7 Hz, 1H), 3.47 (br. s., 2H), 3.02 (q, J=6.8 Hz, 2H), 2.68 (t, J=7.3 Hz, 2H), 1.63 (quin, J=6.9 Hz, 2H), 1.37 (s, 9H).

(6-{[(6-oxo-5,6-dihydro-phenanthridin-2-ylcarbamoyl)-methyl]-amino}-hexyl)-carbamic acid tert-butyl ester

To a stirred suspension of 2-chloro-N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-acetamide (XVIII, Lg=Cl, 65 mg, 0.23 mmol) in N,N-dimethylformamide (2 mL), (6-amino-hexyl)-carbamic acid tert-butyl ester hydrochloride (175 mg, 0.69 mmol) and triethylamine (0.097 mL, 0.69 mmol) were added. The reaction mixture was stirred at room temperature overnight, diluted with dichloromethane, and the resulting solution was washed with water then brine, dried over sodium sulfate and evaporated to dryness. The crude was purified by preparative HPLC on Waters X Terra RP 18 (19×250 mm, 5 μm) column. Mobile phase A was 0.05% ammonium hydroxide/acetonitrile:95/5 and mobile phase B was acetonitrile/water:95/5. Gradient from 10 to 75% B in 15 min. Fractions containing the desired compound were dried, affording 50 mg (47% yield) of the title compound.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 11.62 (br. s., 1H), 9.90 (br. s., 1H), 8.65 (d, J=1.7 Hz, 1H), 8.33 (dd, J=8.5, 1.2 Hz, 1H), 8.30 (d, J=8.0 Hz, 1H), 7.88 (ddd, J=8.3, 7.1, 1.1 Hz, 1H), 7.74 (dd, J=8.7, 1.9 Hz, 1H), 7.65 (t, J=7.6 Hz, 1H), 7.31 (d, J=8.7 Hz, 1H), 6.73 (t, J=5.5 Hz, 1H), 3.27-3.33 (m, 2H), 2.89 (q, J=6.5 Hz, 2H), 2.55 (t, J=7.0 Hz, 2H), 1.97-2.61 (m, 1H), 1.17-1.51 (m, 8H), 1.36 (s, 9H).

Step i_(b) 2-(3-Amino-propylamino)-N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-acetamide hydrochloride

(3-{[(6-oxo-5,6-dihydro-phenanthridin-2-ylcarbamoyl)-methyl]-amino}-propyl)-carbamic acid tert-butyl ester (32 mg, 0.075 mmol) was dissolved in dichloromethane (1 mL) and 4N hydrochloric acid in dioxane (1 mL) was added. The reaction mixture was stirred at room temperature overnight and then evaporated, affording 32 mg (97% yield) of the title compound.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 11.72 (s, 1H), 10.90 (s, 1H), 9.29 (d, J=0.6 Hz, 2H), 8.62 (d, J=2.0 Hz, 1H), 8.35 (dd, J=7.9, 1.2 Hz, 1H), 8.22 (d, J=8.2 Hz, 1H), 7.98 (br. s., 3H), 7.91 (ddd, J=8.2, 7.1, 1.3 Hz, 1H), 7.69 (dd, J=8.8, 2.2 Hz, 1H), 7.68 (ddd, J=7.9, 7.2, 0.9 Hz, 1H), 7.38 (d, J=8.8 Hz, 1H), 4.00 (t, J=4.5 Hz, 2H), 3.11 (br. s., 2H), 2.92 (sxt, J=6.4 Hz, 2H), 2.00 (quin, J=7.6 Hz, 2H).

2-(6-Amino-hexylamino)-N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-acetamide trifluoroacetate

(6-{[(6-oxo-5,6-dihydro-phenanthridin-2-ylcarbamoyl)-methyl]-amino}-hexyl)-carbamic acid tert-butyl ester was dissolved in dichloromethane (5 mL) and trifluoroacetic acid (1.5 mL) was added. The reaction mixture was stirred at room temperature overnight, evaporated, taken up with diethyl ether, filtered and the collected solid was dried under vacuum to afford 30 mg (65% yield) of the title compound as a light-yellow solid.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 11.72 (s, 1H), 10.67 (s, 1H), 8.93 (dt, J=10.7, 5.4 Hz, 2H), 8.58 (d, J=2.1 Hz, 1H), 8.35 (dd, J=8.1, 1.2 Hz, 1H), 8.22 (d, J=8.2 Hz, 1H), 7.91 (ddd, J=8.2, 7.1, 1.4 Hz, 1H), 7.69 (ddd, J=7.9, 7.2, 0.7 Hz, 1H), 7.65 (dd, J=9.0, 2.3 Hz, 1H), 7.67 (br. s., 3H), 7.38 (d, J=8.7 Hz, 1H), 3.99 (t, J=5.4 Hz, 2H), 2.95-3.06 (m, 2H), 2.72-2.85 (m, 2H), 1.64 (quin, J=7.1 Hz, 2H), 1.53 (quin, J=7.0 Hz, 2H), 1.33 (dt, J=6.9, 3.4 Hz, 4H).

Step ii 9-Dimethylamino-11,11-dimethyl-1-(3-{methyl-[(6-oxo-5,6-dihydro-phenanthridin-2-ylcarbamoyl)-methyl]-carbamoyl}-propyl)-2,3,4,11-tetrahydro-naphtho[2,3-g]quinolinium trifluoroacetate (cpd P1)

To a stirred solution of 2-methylamino-N-(6-oxo-5,6-dihydro-phenanthridin-2-yl)-acetamide (3.65 mg, 0.013 mmol) in N,N-dimethylformamide (0.5 mL), N,N-diisopropylethylamine (0.0067 mL, 0.039 mmol) and ATTO 610 NHS ester (XXI) were added under nitrogen, and the reaction was stirred at room temperature for 3 hours. The mixture was then evaporated, and the resulting crude was purified by preparative HPLC on Hypersil (21×250 mm, 5 μm) column. Mobile phase A was 0.1% trifluoroacetic acid/acetonitrile:95/5 and mobile phase B was acetonitrile/water: 95/5. Gradient from 0 to 70% B in 20 min. Fractions containing the desired compound were dried, affording 1.6 mg of the title compound.

MS calculated: 654.3444; MS found: 654.3447; ESI(+) MS: m/z 654 (Mt).

According to this same methodology, but employing the suitable starting materials, the following compounds were also prepared:

9-Dimethylamino-11,11-dimethyl-1-[3-(3-{[(6-oxo-5,6-dihydro-phenanthridin-2-ylcarbamoyl)-methyl]-amino}-propylcarbamoyl)-propyl]-2,3,4,11-tetrahydro-naphtho[2,3-g]quinolinium trifluoroacetate (cpd P2)

MS calculated: 697.3866; MS found: 697.3864

ESI(+) MS: m/z 697 (Mt).

9-Dimethylamino-11,11-dimethyl-1-[3-(6-{[(6-oxo-5,6-dihydro-phenanthridin-2-ylcarbamoyl)-methyl]-amino}-hexylcarbamoyl)-propyl]-2,3,4,11-tetrahydro-naphtho[2,3-g]quinolinium trifluoroacetate (cpd P3)

MS calculated: 739.4337; MS found: 739.4333

ESI(+) MS: m/z 739 (Mt). 

The invention claimed is:
 1. A compound of formula (I):

wherein R is a C₃-C₇ cycloalkyl or heterocyclyl group, each of which further substituted with R₅O—C₁-C₆ alkyl, C₃-C₆ cycloalkyl, heterocyclyl, aryl, R₉—C₁-C₆ alkyl or heteroaryl group, each of which further substituted with one or more substituents independently selected from halogen atom, NR₃R₄, oxo (═O), OR₅ and a substituted C₁-C₆ alkyl group; when simultaneously present, two substituents such as NR₃R₄ and OR₅, may form, taken together, an optionally substituted heterocyclyl group; R₁ is hydrogen or halogen atom; R₃ and R₄ are independently hydrogen atom, R₆R₇N—C₂-C₆ alkyl, R₆O—C₂-C₆ alkyl, an optionally further substituted linear or branched C₁-C₆ alkyl, C₃-C₆ cycloalkyl, or R₃ and R₄, taken together with the nitrogen atom to which they are bonded, form an optionally substituted heterocyclyl group; R₅ is hydrogen atom, or an optionally further substituted linear or branched C₁-C₆ alkyl; R₆ and R₇ are independently hydrogen atom, or an optionally further substituted linear or branched C₁-C₆ alkyl or R₆ and R₇, taken together with the nitrogen atom to which they are bonded, form an optionally substituted heterocyclyl group; R₉ is either a C₃-C₆ cycloalkyl, heterocyclyl, aryl or heteroaryl group further substituted with one or more substituents independently selected from halogen atom, linear or branched C₁-C₆ alkyl NR₃R₄, OR₅, substituted C₁-C₆ alkyl, C₃-C₆ cycloalkyl, heterocyclyl, aryl and heteroaryl group; or a pharmaceutically acceptable salt thereof.
 2. A compound of formula (I) according to claim 1, characterized in that R₃ and R₄ are independently an optionally further substituted linear or branched C₁-C₆ alkyl, C₃-C₆ cycloalkyl, or heteroaryl-C₁-C₆ alkyl group or R₃ and R₄, taken together with the nitrogen atom to which they are bonded, form an optionally substituted heterocyclyl group, such substituent being a halogen atom; R₅ is an optionally further substituted linear or branched C₁-C₆ alkyl group; R₆ and R₇ are independently an optionally further substituted linear or branched C₁-C₆ alkyl group; R₉ is either a heterocyclyl, aryl or heteroaryl group, each of which further substituted with one or more substituents independently selected from halogen atom, linear or branched C₁-C₆ alkyl, or substituted C₁-C₆ alkyl, wherein the substituent is one or more selected from halogen atom and aryl group; or a pharmaceutically acceptable salt thereof.
 3. A compound of formula (I) according to claim 1, characterized in that R is a piperidinyl group further substituted with methoxyethyl, cyclohexyl or R₉-methyl group, each of which further substituted with one or two substituents independently selected from fluorine atom, oxo (═O), methoxy or, when simultaneously present, two substituents form, taken together, a dioxolane ring, and an optionally substituted methyl group, wherein the substituent if present is hydroxyl or methoxy group; R₁ is hydrogen or fluorine atom; R₃ and R₄ are independently an optionally further substituted i-butyl or methyl, cyclopentyl, or furylmethyl group, or R₃ and R₄, taken together with the nitrogen atom to which they are bonded, form an optionally substituted piperidinyl group, such substituent being a chlorine atom; R₉ is a piperidinyl, phenyl, thiazolyl, pyrazolyl or pyrrolyl group, each of which further substituted with one or more substituents independently selected from chlorine, fluorine or bromine atom, methyl, ethyl, isopropyl, methoxy, ethoxy, propyloxy, isopropyloxy, dimethylamino group or substituted methyl, wherein the substituent is one or more selected from fluorine atom and phenyl group; or an optionally substituted phenyl, pyrrolyl or pyridyl group fused with a phenyl or a pyrrole ring, wherein the substituent is one or more selected from isopropyl group; or a pharmaceutically acceptable salt thereof.
 4. A compound of formula (I) according to claim 1, selected from the group consisting of: 2-[1-(cis-4-methoxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(trans-4-methoxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[cis-4-(hydroxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[trans-4-(hydroxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[cis-4-(methoxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[trans-4-(methoxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(1,4-dioxaspiro[4.5]dec-8-yl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[4-(dimethylamino)benzyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4-fluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(2-fluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(3-fluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[(1-methyl-1H-pyrrol-2-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 3-oxo-2-{1-[4-(trifluoromethyDbenzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; 3-oxo-2-[1-(quinolin-2-ylmethyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(2,4-difluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(3,4-dimethylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(2-methylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(2-bromobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(3-bromobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4-bromobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 3-oxo-2-{1-[3-(trifluoromethyl)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; 3-oxo-2-{1-[2-(trifinoromethyl)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(3-methylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[(4-methyl-1,3-thiazol-5-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[(1-benzylpiperidin-4-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(1H-indol-4-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(1H-indol-5-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(1H-indol-6-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4-methylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 3-oxo-2-(1-[1-(propan-2-yl)-1H-indol-3-yl]methyllpiperidin-4-yl)-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[(1-methyl-1H-pyrazol-4-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[(1,5-dimethyl-1H-pyrazol-4-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(3-methoxybenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[(3-methylthiophen-2-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 3-oxo-2-[1-(4-propoxybenzyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide; 3-oxo-2-{1-[4-(propan-2-yl)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4-methoxybenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(3-ethoxybenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 3-oxo-2-{1-[2-(propan-2-yloxy)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(3-chlorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4-ethylbenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 3-oxo-2-{1-[4-(propan-2-yloxy)benzyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[(5-rnethylthiophen-2-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(cis-4-hydroxycyclohexyppiperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(trans-4-hydroxycyclohexyppiperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[cis-4-(acetylamino)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[trans-4-(acetylamino)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 3-oxo-2-{1-[cis-4-(trifluoromethyl)cyclohexyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; 3-oxo-2-{1-[trans-4-(trifluoromethyl)cyclohexyl]piperidin-4-yl}-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[cis-4-(dimethylamino)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[trans-4-(dimethylamino)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(cis-4-carbamoylcyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(trans-4-carbamoylcyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[cis-4-(3-chlorophenyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[trans-4-(3-chlorophenyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(cis-4-cyanocyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(trans-4-cyanocyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{4-[(4,4-difluoropiperidin-1-yl)methyl]phenyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{4-[(4-methoxypiperidin-1-yl)methyl]phenyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{4-[(4-hydroxypiperidin-1-yl)methyl]phenyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-(4-{[4-(methoxymethyl)piperidin-1-yl]methyl}phenyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-(4-{[4-(hydroxymethyl)piperidin-1-yl]methyl}phenyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4,4-difluorocyclohexyDazetidin-3-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(cis-4-methoxycyclohexyl)azetidin-3-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(trans-4-methoxycyclohexypazetidin-3-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(cis-4-hydroxycyclohexyeazetidin-3-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(trans-4-hydroxycyclohexyeazetidin-3-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[cis-4-(methoxymethyl)cyclohexyl]azetidin-3-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[trans-4-(methoxymethyl)cyclohexyl]azetidin-3-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[cis-4-(hydroxymethyl)cyclohexyl]azetidin-3-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-{1-[trans-4-(hydroxymethyl)cyclohexyl]azetidin-3-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-[1-(cis-4-methoxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-[1-(trans-4-methoxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-[1-(cis-4-hydroxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-[1-(trans-4-hydroxycyclohexyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-{1-[cis-4-(methoxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-{1-[trans-4-(methoxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-{1-[cis-4-(hydroxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-{1-[trans-4-(hydroxymethyl)cyclohexyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(1,4-dioxaspiro[4.5]dec-8-yl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-[1-(4-fluorobenzyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-3-oxo-2-[1-(quinolin-2-ylmethyDpiperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-{1-[(3-methylthiophen-2-yl)methyl]piperidin-4-yl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-[1-(1H-indol-6-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-[1-(1H-indol-5-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-[1-(1H-indol-4-ylmethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-3-oxo-2-(1-{[1-(propan-2-yl)-1H-indol-3-yl]methyl}piperidin-4-yl)-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-2-{[1-(4-fluorobenzyl)piperidin-4-yl]methyl}-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-({1-[(4,4-difluorocyclohexyl)methyl]piperidin-4-yl}methyl)-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4,4-difluorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4,4-difluorocyclohexyl)-piperidin-4-yl]-6-chloro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4,4-difluorocyclohexyl)-piperidin-4-yl]-7-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4,4-difluorocyclohexyl)-piperidin-4-yl]-5-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide; 6-fluoro-3-oxo-2-[1-(4-oxocyclohexyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide; 5-fluoro-3-oxo-2-[1-(4-oxocyclohexyl)piperidin-4-yl]-2,3-dihydro-1H-isoindole-4-carboxamide; 2-[1-(4,4-dichlorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide and 2-[1-(2-methoxyethyl)piperidin-4-yl]-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide or a pharmaceutically acceptable salt thereof.
 5. A process for the preparation of a compounds of the formula (I) as defined in claim 1, which process comprises one of the following sequence of steps: SEQUENCE A): either Step a) halogenating a compound of formula (IX):

wherein R₁ is as defined in claim 1; Step b) cyano-de-aminating the resultant compound of formula (VIII):

wherein Hal is halogen such as Cl, Br, I and R₁ is as defined above; Step c) hydrolyzing the resultant compound of formula (VII):

wherein Hal and R₁ are as defined above and Step d) hydrolyzing the resultant compound of formula (VI):

wherein Hal and R₁ are as defined above, to give a compound of the formula (V)

wherein Hal and R₁ are as defined above; or Step i) halogenating a compound of formula (X):

wherein R₁ is as defined above; Step e) esterifying the resultant compound of formula (V) as defined above and either Step f) cyclizing the resultant compound of formula (IV):

wherein T is a C₁-C₆ alkyl or aryl C₁-C₆ alkyl group; Hal and R₁ are as defined above, by reaction with a suitable amine (XII) of formula R—NH₂, wherein R is as defined in claim 1 and Step g) cyano-de-halogenating the resultant compound of formula (III):

wherein Hal, R and R₁ are as defined above, to give a compound of formula (II):

wherein R and R₁ are as defined above, or Step g′) cyano-de-halogenating a compound of formula (IV) as defined above, and Step f′) cyclizing the resultant compound of formula (XI):

wherein T and R₁ are as defined above by reacting with a suitable amine of formula (XII) as defined above and Step h) hydrolyzing the resultant compound of formula (II) as defined above to give a compound of formula (I) as defined above; or SEQUENCE B): Step l) a reductive amination step performed on a compound of formula (XIII):

wherein R₁ is as defined above; Step m) a Diels-Alder reaction step performed on the resultant compound of formula (XIV):

wherein R and R₁ are as defined above; Step n) aromatizing the resultant compound of formula (XV):

wherein R and R₁ are as defined above; Step o) amidating the resultant compound of formula (XVI):

wherein R and R₁ are as defined above so as to obtain a compound of formula (I) as defined above, or, alternatively; Step p) performing a reductive amination step on a compound of formula (XVII):

wherein R₁ is as defined above, so as to obtain a compound of the formula (XIV) as defined above, which is then subjected to the sequence of reactions m), n) and o) above described so as to obtain a compound of formula (I) as above defined and, if necessary or wanted, converting a compound of formula (I) into a different compound of formula (I) by known chemical reactions; and/or, if desired, converting a compound of formula (I) into a pharmaceutically acceptable salt thereof or converting a salt into a free compound of formula (I).
 6. A pharmaceutical composition comprising a therapeutically effective amount of a compound of formula (I), as defined in claim 1, and at least one pharmaceutically acceptable carrier and/or diluent.
 7. A pharmaceutical composition according to claim 6 further comprising one or more chemotherapeutic agents.
 8. A product comprising a compound of formula (I) as defined in claim 1 or a pharmaceutical composition thereof comprising a therapeutically effective amount of said compound and at least one pharmaceutically acceptable carrier and/or diluent, and one or more chemotherapeutic agents, as a combined preparation for simultaneous, separate or sequential use in anticancer therapy. 